PeerFinder PeerFinder PeerFinder PeerFinder Class

Definition

Enables you to discover other instances of your app on nearby devices and create a socket connection between the peer apps by using a tap gesture or by browsing. For creating Bluetooth socket connections on Windows 8.1 and later, use Windows.Devices.Bluetooth.Rfcomm instead.

public : static class PeerFinder
public static class PeerFinder
Public Static Class PeerFinder
// This class does not provide a public constructor.
Attributes
Windows 10 requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Examples

var started = false;

// Click event for "Advertise" button.
function advertiseForPeers(launchedFromTap) {
    Windows.Networking.Proximity.PeerFinder.displayName = displayNameTextBox.Text;

    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.triggered) {

        Windows.Networking.Proximity.PeerFinder.addEventListener(
            "triggeredconnectionstatechanged", triggeredConnectionStateChanged);

        id("messageDiv").innerHTML +=
            "You can tap to connect a peer device that is " +
            "also advertising for a connection.<br />";
    } else {
        id("messageDiv").innerHTML +=
      "Tap to connect is not supported.<br />";
    }

    if (!launchedFromTap) {
        if (!(Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
              Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)) {
            id("messageDiv").innerHTML +=
                "Peer discovery using Wi-Fi Direct is not supported.<br />";
        }
    }

    if (!started) {
        Windows.Networking.Proximity.PeerFinder.start();
        started = true;
    }
}

function triggeredConnectionStateChanged(e) {
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.peerFound) {
        id("messageDiv").innerHTML +=
            "Peer found. You may now pull your devices out of proximity.<br />";
    }
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.completed) {
        id("messageDiv").innerHTML += "Connected. You may now send a message.<br />";
        sendMessage(e.socket);
    }
}


// Click event for "Browse" button.
function findPeers() {
    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.browse) {

        Windows.Networking.Proximity.PeerFinder.findAllPeersAsync().done(
    function (peerInfoCollection) {
        if (peerInfoCollection.length > 0) {
            // Connect to first peer found - example only.
            // In your app, provide the user with a list of available peers.
            connectToPeer(peerInfoCollection[0]);
        }
    },
    function (err) {
        id("messageDiv").innerHTML += "Error finding peers: " + err + "<br />";
    });
    } else {
        id("messageDiv").innerHTML +=
  "Peer discovery using Wi-Fi Direct is not supported.<br />";
    }
}

function connectToPeer(peerInfo) {
    id("messageDiv").innerHTML += ("Peer found. Connecting to " + peerInfo.displayName + "<br />");
    Windows.Networking.Proximity.PeerFinder.connectAsync(peerInfo).done(
        function (socket) {
            id("messageDiv").innerHTML += "Connection successful. You may now send messages.<br />";
            sendMessage(socket);
        },
        function (err) {
            id("messageDiv").innerHTML += "Connection failed: " + err + "<br />";
        });

    requestingPeer = null;
}

function stopFindingPeers() {
    Windows.Networking.Proximity.PeerFinder.stop();
    started = false;
    if (proximitySocket != null) { closeSocket(); }
}

// Handle external connection requests.
var requestingPeer;

function connectionRequested(e) {
    id("messageDiv").innerHTML +=
        "Connection requested by " + e.peerInformation.DisplayName + ". " +
        "Click 'Accept Connection' to connect.";
    requestingPeer = e.PeerInformation;
}

function acceptConnection() {
    if (requestingPeer == null) {
        id("messageDiv").innerHTML += "No peer connection has been requested.";
        return;
    }

    connectToPeer(requestingPeer);
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName;
    Windows.Networking.Proximity.PeerFinder.ConnectionRequested += ConnectionRequested;

    // If activated from launch or from the background, create a peer connection.
    var args = e.Parameter as Windows.ApplicationModel.Activation.LaunchActivatedEventArgs;
    if (args != null && args.Kind == Windows.ApplicationModel.Activation.ActivationKind.Launch)
    {
        if (args.Arguments == "Windows.Networking.Proximity.PeerFinder:StreamSocket")
        {
            AdvertiseForPeersButton_Click(null, null);
        }
    }
}

protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
    if (_started)
    {
        // Detach the callback handler (there can only be one PeerConnectProgress handler).
        Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged -= TriggeredConnectionStateChanged;
        // Detach the incoming connection request event handler.
        Windows.Networking.Proximity.PeerFinder.ConnectionRequested -= ConnectionRequested;
        Windows.Networking.Proximity.PeerFinder.Stop();
        CloseSocket();
        _started = false;
    }
}

// Write a message to MessageBlock on the UI thread.
private Windows.UI.Core.CoreDispatcher messageDispatcher = Window.Current.CoreWindow.Dispatcher;

async private void WriteMessageText(string message, bool overwrite = false)
{
    await messageDispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        () =>
        {
            if (overwrite)
                MessageBlock.Text = message;
            else
                MessageBlock.Text += message;
        });
}

bool _started = false;

// Click event handler for "Advertise" button.
private void AdvertiseForPeersButton_Click(object sender, RoutedEventArgs e)
{
    if (_started) 
    {
        WriteMessageText("You are already advertising for a connection.\n");
        return; 
    }

    Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text;

    if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) ==
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered)
    {
        Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged +=
            TriggeredConnectionStateChanged;

        WriteMessageText("You can tap to connect a peer device that is " +
                         "also advertising for a connection.\n");
    }
    else
    {
        WriteMessageText("Tap to connect is not supported.\n");
    }

    if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
         Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) !=
         Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)
    {
        WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.\n");
    }

   Windows.Networking.Proximity.PeerFinder.Start();
   _started = true;
}

private void TriggeredConnectionStateChanged(
    object sender,
    Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs e)
{
    if (e.State == Windows.Networking.Proximity.TriggeredConnectState.PeerFound)
    {
        WriteMessageText("Peer found. You may now pull your devices out of proximity.\n");
    }
    if (e.State == Windows.Networking.Proximity.TriggeredConnectState.Completed)
    {
        WriteMessageText("Connected. You may now send a message.\n");
        SendMessage(e.Socket);
    }
}

// Click event handler for "Browse" button.
async private void FindPeersButton_Click(object sender, RoutedEventArgs e)
{
    if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
         Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) !=
         Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)
    {
        WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.\n");
        return;
    }

    try
    {
        var peerInfoCollection = await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync();
        if (peerInfoCollection.Count > 0)
        {
            // Connect to first peer found - example only.
            // In your app, provide the user with a list of available peers.
            ConnectToPeer(peerInfoCollection[0]);
        }
    }
    catch (Exception err)
    {
        WriteMessageText("Error finding peers: " + err.Message + "\n");
    }
}

async private void ConnectToPeer(Windows.Networking.Proximity.PeerInformation peerInfo)
{
    WriteMessageText("Peer found. Connecting to " + peerInfo.DisplayName + "\n");
    try
    {
        Windows.Networking.Sockets.StreamSocket socket =
            await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo);

        WriteMessageText("Connection successful. You may now send messages.\n");
        SendMessage(socket);
    }
    catch (Exception err)
    {
        WriteMessageText("Connection failed: " + err.Message + "\n");
    }

    requestingPeer = null;
}

// Click event handler for "Stop" button.
private void StopFindingPeersButton_Click(object sender, RoutedEventArgs e)
{
    _started = false;
    Windows.Networking.Proximity.PeerFinder.Stop();
    if (proximitySocket != null) { CloseSocket(); }
}

// Handle external connection requests.
Windows.Networking.Proximity.PeerInformation requestingPeer;

private void ConnectionRequested(object sender,
    Windows.Networking.Proximity.ConnectionRequestedEventArgs e)
{
    requestingPeer = e.PeerInformation;
    WriteMessageText("Connection requested by " + requestingPeer.DisplayName + ". " +
        "Click 'Accept Connection' to connect.");
}

private void AcceptConnectionButton_Click(object sender, RoutedEventArgs e)
{
    if (requestingPeer == null)
    {
        WriteMessageText("No peer connection has been requested.");
        return;
    }

    ConnectToPeer(requestingPeer);
}
Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName
    AddHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested

    ' If activated from launch or from the background, create a peer connection.
    Dim args = TryCast(e.Parameter, Windows.ApplicationModel.Activation.LaunchActivatedEventArgs)
    If args IsNot Nothing AndAlso args.Kind = Windows.ApplicationModel.Activation.ActivationKind.Launch Then

        If args.Arguments = "Windows.Networking.Proximity.PeerFinder:StreamSocket" Then
            AdvertiseForPeersButton_Click()
        End If
    End If
End Sub

Protected Overrides Sub OnNavigatingFrom(e As Navigation.NavigatingCancelEventArgs)
    If _started Then
        ' Detach the callback handler (there can only be one PeerConnectProgress handler).
        RemoveHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged, AddressOf TriggeredConnectionStateChanged
        ' Detach the incoming connection request event handler.
        RemoveHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested
        Windows.Networking.Proximity.PeerFinder.Stop()
        CloseSocket()
        _started = False
    End If
End Sub

' Write a message to MessageBlock on the UI thread.
Private Async Sub WriteMessageText(message As String, Optional overwrite As Boolean = False)
    Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        Sub()
            If overwrite Then
                MessageBlock.Text = message
            Else
                MessageBlock.Text &= message
            End If
        End Sub)
End Sub

Private _started As Boolean = False

' Click event handler for "Advertise" button.
Private Sub AdvertiseForPeersButton_Click()

    If _started Then
        WriteMessageText("You are already advertising for a connection." & vbCrLf)
        Return
    End If

    Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text

    If ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) =
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) Then

        AddHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged,
            AddressOf TriggeredConnectionStateChanged

        WriteMessageText("You can tap to connect a peer device that is " &
                         "also advertising for a connection." & vbCrLf)
    Else
        WriteMessageText("Tap to connect is not supported." & vbCrLf)
    End If

    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
    End If

    Windows.Networking.Proximity.PeerFinder.Start()
    _started = True
End Sub

Private Sub TriggeredConnectionStateChanged(
    sender As Object,
    e As Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs)

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.PeerFound Then

        WriteMessageText("Peer found. You may now pull your devices out of proximity." & vbCrLf)
    End If

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.Completed Then
        WriteMessageText("Connected. You may now send a message." & vbCrLf)
        SendMessage(e.Socket)
    End If
End Sub

' Click event handler for "Browse" button.
Private Async Sub FindPeersButton_Click()
    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
        Return
    End If

    Try
        Dim peerInfoCollection = Await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync()
        If peerInfoCollection.Count > 0 Then
            ' Connect to first peer found - example only.
            ' In your app, provide the user with a list of available peers.
            ConnectToPeer(peerInfoCollection(0))
        End If
    Catch err As Exception
        WriteMessageText("Error finding peers: " & err.Message & vbCrLf)
    End Try
End Sub

Private Async Sub ConnectToPeer(peerInfo As Windows.Networking.Proximity.PeerInformation)

    WriteMessageText("Peer found. Connecting to " & peerInfo.DisplayName & vbCrLf)
    Try
        Dim socket = Await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo)

        WriteMessageText("Connection successful. You may now send messages." & vbCrLf)
        SendMessage(socket)
    Catch err As Exception
        WriteMessageText("Connection failed: " & err.Message & vbCrLf)
    End Try

    requestingPeer = Nothing
End Sub

' Click event handler for "Stop" button.
Private Sub StopFindingPeersButton_Click()

    _started = False
    Windows.Networking.Proximity.PeerFinder.Stop()
    If proximitySocket IsNot Nothing Then CloseSocket()
End Sub

' Handle external connection requests.
Private requestingPeer As Windows.Networking.Proximity.PeerInformation

Private Sub ConnectionRequested(sender As Object,
    e As Windows.Networking.Proximity.ConnectionRequestedEventArgs)

    requestingPeer = e.PeerInformation

    WriteMessageText("Connection requested by " & requestingPeer.DisplayName & ". " &
        "Click 'Accept Connection' to connect.")
End Sub

Private Sub AcceptConnectionButton_Click()
    If requestingPeer Is Nothing Then
        WriteMessageText("No peer connection has been requested.")
        Return
    End If

    ConnectToPeer(requestingPeer)
End Sub

Remarks

Important

The Proximity APIs do not provide authentication. You should avoid exchanging sensitive data with these APIs.

Properties

AllowBluetooth AllowBluetooth AllowBluetooth AllowBluetooth

Specifies whether the PeerFinder class may connect a StreamSocket object by using Bluetooth.

public : static Platform::Boolean AllowBluetooth { get; set; }
public static bool AllowBluetooth { get; set; }
Public Static ReadWrite Property AllowBluetooth As bool
var bool = Windows.Networking.Proximity.PeerFinder.allowBluetooth;
peerFinder.allowBluetooth = bool;
Value
Platform::Boolean bool bool bool

True if the PeerFinder class may connect a StreamSocket object by using Bluetooth; otherwise false. The default is true.

Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]
See Also

AllowInfrastructure AllowInfrastructure AllowInfrastructure AllowInfrastructure

Specifies whether the PeerFinder class may connect to a StreamSocket object using TCP/IP.

public : static Platform::Boolean AllowInfrastructure { get; set; }
public static bool AllowInfrastructure { get; set; }
Public Static ReadWrite Property AllowInfrastructure As bool
var bool = Windows.Networking.Proximity.PeerFinder.allowInfrastructure;
peerFinder.allowInfrastructure = bool;
Value
Platform::Boolean bool bool bool

True if the PeerFinder class may connect to a StreamSocket object using TCP/IP; otherwise false.

Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

AllowWiFiDirect AllowWiFiDirect AllowWiFiDirect AllowWiFiDirect

Specifies whether the PeerFinder class may connect a StreamSocket object by using Wi-Fi Direct.

public : static Platform::Boolean AllowWiFiDirect { get; set; }
public static bool AllowWiFiDirect { get; set; }
Public Static ReadWrite Property AllowWiFiDirect As bool
var bool = Windows.Networking.Proximity.PeerFinder.allowWiFiDirect;
peerFinder.allowWiFiDirect = bool;
Value
Platform::Boolean bool bool bool

True if the PeerFinder class may connect a StreamSocket object by using Wi-Fi Direct; otherwise false. The default is true.

Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Remarks

Setting the AllowWiFiDirect property to false disables the ability to browse for peer apps using Wi-Fi Direct. You will not be able to use the FindAllPeersAsync method to browse for remote peers.

Windows Phone 8

Wi-Fi Direct is not supported on Windows Phone 8.

See Also

AlternateIdentities AlternateIdentities AlternateIdentities AlternateIdentities

Gets a list of alternate appId values to match with peer applications on other platforms.

public : static IMap<Platform::String, Platform::String> AlternateIdentities { get; }
public static IDictionary<string, string> AlternateIdentities { get; }
Public Static ReadOnly Property AlternateIdentities As IDictionary<string, string>
var iDictionary = Windows.Networking.Proximity.PeerFinder.alternateIdentities;
Value
IMap<Platform::String, Platform::String> IDictionary<string, string> IDictionary<string, string> IDictionary<string, string>

A list of alternate appId values to match with peer applications on other platforms.

Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Remarks

The AlternateIdentities property is used to add alternate proximity app Ids that match the proximity app Ids of peer apps running on other platforms. The PeerFinder class uses the alternate app Ids to match a peer app running on a Windows 8 computer with a peer app running on another platform. For example, if you create an app for Windows 8 and also create the same app for Windows Phone, the apps will not have the same unique app Id on both platforms. You can use the PeerFinder class to match the peer apps by adding the app Id from the Windows Phone to the AlternateIdentities property of your Windows app, and by adding the app Id for your Windows app to the alternate identities of the Windows Phone.

The other platform must also support adding alternate identities so that the proximity app Id can be specified on that platform. You must include the proximity app Id on the other platform for the PeerFinder class to connect your apps when tapping with a Windows device. The format of the alternate identity string for a specific platform is determined by the implementation of the other platform. For example, to get the correct alternate identity string for Windows Phone, refer to the Windows Phone proximity API documentation.

The format of the proximity app Id is <package family name>!<app Id>. You can get the package family name from the Windows.ApplicationModel.Package.Current.Id.FamilyName property. You must copy the app Id value from the Id attribute of the Application element in the package manifest for your app. For Example, PeerFinder.Add("WindowsPhone", "{1c6379c1-9d5e-4254-8f4c-be7ea24057d1}") adds a Windows Phone 8 app id as an alternate identity in your Windows 8 app. PeerFinder.Add("Windows", "b3c3e7ef-371a-464f-a75e-95ddbdcaf974_7fed2v891h66p!App") adds a Windows 8 app id as an alternate identity in a Windows Phone 8 app.

Browsing within wireless range (FindAllPeersAsync)

When you connect peer apps by browsing for devices within wireless range using the FindAllPeersAsync method, you can only match one app Id at a time. By default peer matching when browsing uses the Windows 8 proximity app Id . You can browse to connect peer apps running on different platforms by adding a unique "browse" app Id to the AlternateIdentities property. You can then add that same "browse" app Id to your peer app on the other platforms. If the "browse" alternate identity strings match, then the PeerFinder class can find the peer apps when you call the FindAllPeersAsync method.

See Also

DiscoveryData DiscoveryData DiscoveryData DiscoveryData

Gets or sets user or device data to include during device discovery.

public : static IBuffer DiscoveryData { get; set; }
public static IBuffer DiscoveryData { get; set; }
Public Static ReadWrite Property DiscoveryData As IBuffer
var iBuffer = Windows.Networking.Proximity.PeerFinder.discoveryData;
peerFinder.discoveryData = iBuffer;
Value
IBuffer IBuffer IBuffer IBuffer

User or device data to include during device discovery. Must be less than 32 bytes.

Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
proximity

Examples

// Default to the peer role.
Windows.Networking.Proximity.PeerRole appRole = Windows.Networking.Proximity.PeerRole.Peer;
bool launchedByTap = false;

protected override void OnNavigatedTo(NavigationEventArgs e)
{
    LaunchActivatedEventArgs launchArgs = e.Parameter as LaunchActivatedEventArgs;

    if (launchArgs.Arguments.Contains("Windows.Networking.Proximity.PeerFinder:StreamSocket"))
    {
        launchedByTap = true;

        if (launchArgs.Arguments.Contains("Role=Host"))
        {
            appRole = Windows.Networking.Proximity.PeerRole.Host;
        }
        else if (launchArgs.Arguments.Contains("Role=Client"))
        {
            appRole = Windows.Networking.Proximity.PeerRole.Client;
        }
        else
        {
            appRole = Windows.Networking.Proximity.PeerRole.Peer;
        }
    }
}

bool started = false;

// Click event for "Advertise" button.
void AdvertiseForPeers(object sender, RoutedEventArgs e)
{
    if (!started)
    {
        Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text;

        if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
             Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) ==
             Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered)
        {
            Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged +=
                TriggeredConnectionStateChanged;

            WriteMessageText("You can tap to connect a peer device that is " +
                             "also advertising for a connection.
"); } else { WriteMessageText("Tap to connect is not supported.
"); } if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); } // Set the peer role selected by the user. if (launchedByTap) { Windows.Networking.Proximity.PeerFinder.Role = appRole; } else { switch (GetRoleFromUser()) { case "Peer": Windows.Networking.Proximity.PeerFinder.Role = Windows.Networking.Proximity.PeerRole.Peer; break; case "Host": Windows.Networking.Proximity.PeerFinder.Role = Windows.Networking.Proximity.PeerRole.Host; break; case "Client": Windows.Networking.Proximity.PeerFinder.Role = Windows.Networking.Proximity.PeerRole.Client; break; } } // Set discoveryData property with user supplied text. var discData = GetDiscoveryDataFromUser(); var writer = new Windows.Storage.Streams.DataWriter( new Windows.Storage.Streams.InMemoryRandomAccessStream()); writer.WriteString(discData); Windows.Networking.Proximity.PeerFinder.DiscoveryData = writer.DetachBuffer(); Windows.Networking.Proximity.PeerFinder.Start(); started = true; } } // Write a message to MessageBlock on the UI thread. private Windows.UI.Core.CoreDispatcher messageDispatcher = Window.Current.CoreWindow.Dispatcher; async private void WriteMessageText(string message, bool overwrite = false) { await messageDispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () => { if (overwrite) MessageBlock.Text = message; else MessageBlock.Text += message; }); }
// Default to the peer role.
var appRole = Windows.Networking.Proximity.PeerRole.peer;
var launchedFromTap = false; 

app.onactivated = function (args) {
    if (args.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) {
        Windows.Networking.Proximity.PeerFinder.addEventListener("connectionrequested", connectionRequested);

        // Detect if app launched from a tap.
        if ((args.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) &&
            (args.detail.arguments === "Windows.Networking.Proximity.PeerFinder:StreamSocket")) {

            launchedFromTap = true; 

            if (args.detail.arguments.search("Role=Host") !== -1) { 
                appRole = Windows.Networking.Proximity.PeerRole.host; 
            } 
            else if (args.detail.arguments.search("Role=Client") !== -1) { 
                appRole = Windows.Networking.Proximity.PeerRole.client; 
            } 
            else { 
                appRole = Windows.Networking.Proximity.PeerRole.peer; 
            } 
        } 
    }

    advertiseForPeers(true);

    args.setPromise(WinJS.UI.processAll());
}

var started = false;

// Click event for "Advertise" button.
function advertiseForPeers(launchedFromTap) {
    Windows.Networking.Proximity.PeerFinder.displayName = displayNameTextBox.Text;

    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.triggered) {

        Windows.Networking.Proximity.PeerFinder.addEventListener(
            "triggeredconnectionstatechanged", triggeredConnectionStateChanged);

        id("messageDiv").innerHTML +=
            "You can tap to connect a peer device that is " +
            "also advertising for a connection.<br />";
    } else {
        id("messageDiv").innerHTML +=
            "Tap to connect is not supported.<br />";
    }

    if (!launchedFromTap) {
        if (!(Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
              Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)) {
            id("messageDiv").innerHTML +=
                "Peer discovery using Wi-Fi Direct is not supported.<br />";
        }
    }       

    if (!started) {
        // Set the peer role selected by the user.  
        if (launchedByTap) { 
            Windows.Networking.Proximity.PeerFinder.role = appRole; 
        } 
        else { 
            switch (getRoleFromUser()) { 
                case "peer": 
                    Windows.Networking.Proximity.PeerFinder.role = 
                        Windows.Networking.Proximity.PeerRole.peer; 
                    break; 
                case "host": 
                    Windows.Networking.Proximity.PeerFinder.role = 
                        Windows.Networking.Proximity.PeerRole.host; 
                    break; 
                case "client": 
                    Windows.Networking.Proximity.PeerFinder.role = 
                        Windows.Networking.Proximity.PeerRole.client; 
                    break; 
            } 
        } 

        // Set discoveryData property with user supplied text. 
        var discData = getDiscoveryDataFromUser();
        var writer = Windows.Storage.Streams.DataWriter(
            new Windows.Storage.Streams.InMemoryRandomAccessStream()); 
        writer.writeString(discData); 
        Windows.Networking.Proximity.PeerFinder.discoveryData = 
            writer.detachBuffer(); 

        Windows.Networking.Proximity.PeerFinder.start();
        started = true;
    }
}

Remarks

Windows Phone 8.x app: This property is not supported. Setting it has no effect and no data is returned from this property on a phone.

See Also

DisplayName DisplayName DisplayName DisplayName

Gets or sets the name that identifies your computer to remote peers.

public : static Platform::String DisplayName { get; set; }
public static string DisplayName { get; set; }
Public Static ReadWrite Property DisplayName As string
var string = Windows.Networking.Proximity.PeerFinder.displayName;
peerFinder.displayName = string;
Value
Platform::String string string string

The name that identifies your computer to remote peers.

Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Examples

var started = false;

// Click event for "Advertise" button.
function advertiseForPeers(launchedFromTap) {
    Windows.Networking.Proximity.PeerFinder.displayName = displayNameTextBox.Text;

    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.triggered) {

        Windows.Networking.Proximity.PeerFinder.addEventListener(
            "triggeredconnectionstatechanged", triggeredConnectionStateChanged);

        id("messageDiv").innerHTML +=
            "You can tap to connect a peer device that is " +
            "also advertising for a connection.<br />";
    } else {
        id("messageDiv").innerHTML +=
      "Tap to connect is not supported.<br />";
    }

    if (!launchedFromTap) {
        if (!(Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
              Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)) {
            id("messageDiv").innerHTML +=
                "Peer discovery using Wi-Fi Direct is not supported.<br />";
        }
    }

    if (!started) {
        Windows.Networking.Proximity.PeerFinder.start();
        started = true;
    }
}

function triggeredConnectionStateChanged(e) {
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.peerFound) {
        id("messageDiv").innerHTML +=
            "Peer found. You may now pull your devices out of proximity.<br />";
    }
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.completed) {
        id("messageDiv").innerHTML += "Connected. You may now send a message.<br />";
        sendMessage(e.socket);
    }
}


// Click event for "Browse" button.
function findPeers() {
    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.browse) {

        Windows.Networking.Proximity.PeerFinder.findAllPeersAsync().done(
    function (peerInfoCollection) {
        if (peerInfoCollection.length > 0) {
            // Connect to first peer found - example only.
            // In your app, provide the user with a list of available peers.
            connectToPeer(peerInfoCollection[0]);
        }
    },
    function (err) {
        id("messageDiv").innerHTML += "Error finding peers: " + err + "<br />";
    });
    } else {
        id("messageDiv").innerHTML +=
  "Peer discovery using Wi-Fi Direct is not supported.<br />";
    }
}

function connectToPeer(peerInfo) {
    id("messageDiv").innerHTML += ("Peer found. Connecting to " + peerInfo.displayName + "<br />");
    Windows.Networking.Proximity.PeerFinder.connectAsync(peerInfo).done(
        function (socket) {
            id("messageDiv").innerHTML += "Connection successful. You may now send messages.<br />";
            sendMessage(socket);
        },
        function (err) {
            id("messageDiv").innerHTML += "Connection failed: " + err + "<br />";
        });

    requestingPeer = null;
}

function stopFindingPeers() {
    Windows.Networking.Proximity.PeerFinder.stop();
    started = false;
    if (proximitySocket != null) { closeSocket(); }
}

// Handle external connection requests.
var requestingPeer;

function connectionRequested(e) {
    id("messageDiv").innerHTML +=
        "Connection requested by " + e.peerInformation.DisplayName + ". " +
        "Click 'Accept Connection' to connect.";
    requestingPeer = e.PeerInformation;
}

function acceptConnection() {
    if (requestingPeer == null) {
        id("messageDiv").innerHTML += "No peer connection has been requested.";
        return;
    }

    connectToPeer(requestingPeer);
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName;
    Windows.Networking.Proximity.PeerFinder.ConnectionRequested += ConnectionRequested;

    // If activated from launch or from the background, create a peer connection.
    var args = e.Parameter as Windows.ApplicationModel.Activation.LaunchActivatedEventArgs;
    if (args != null && args.Kind == Windows.ApplicationModel.Activation.ActivationKind.Launch)
    {
        if (args.Arguments == "Windows.Networking.Proximity.PeerFinder:StreamSocket")
        {
            AdvertiseForPeersButton_Click(null, null);
        }
    }
}

protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
    if (_started)
    {
        // Detach the callback handler (there can only be one PeerConnectProgress handler).
        Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged -= TriggeredConnectionStateChanged;
        // Detach the incoming connection request event handler.
        Windows.Networking.Proximity.PeerFinder.ConnectionRequested -= ConnectionRequested;
        Windows.Networking.Proximity.PeerFinder.Stop();
        CloseSocket();
        _started = false;
    }
}

// Write a message to MessageBlock on the UI thread.
private Windows.UI.Core.CoreDispatcher messageDispatcher = Window.Current.CoreWindow.Dispatcher;

async private void WriteMessageText(string message, bool overwrite = false)
{
    await messageDispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        () =>
        {
            if (overwrite)
                MessageBlock.Text = message;
            else
                MessageBlock.Text += message;
        });
}

bool _started = false;

// Click event handler for "Advertise" button.
private void AdvertiseForPeersButton_Click(object sender, RoutedEventArgs e)
{
    if (_started) 
    {
        WriteMessageText("You are already advertising for a connection.
"); return; } Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text; if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) == Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) { Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged += TriggeredConnectionStateChanged; WriteMessageText("You can tap to connect a peer device that is " + "also advertising for a connection.
"); } else { WriteMessageText("Tap to connect is not supported.
"); } if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); } Windows.Networking.Proximity.PeerFinder.Start(); _started = true; } private void TriggeredConnectionStateChanged( object sender, Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs e) { if (e.State == Windows.Networking.Proximity.TriggeredConnectState.PeerFound) { WriteMessageText("Peer found. You may now pull your devices out of proximity.
"); } if (e.State == Windows.Networking.Proximity.TriggeredConnectState.Completed) { WriteMessageText("Connected. You may now send a message.
"); SendMessage(e.Socket); } } // Click event handler for "Browse" button. async private void FindPeersButton_Click(object sender, RoutedEventArgs e) { if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); return; } try { var peerInfoCollection = await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync(); if (peerInfoCollection.Count > 0) { // Connect to first peer found - example only. // In your app, provide the user with a list of available peers. ConnectToPeer(peerInfoCollection[0]); } } catch (Exception err) { WriteMessageText("Error finding peers: " + err.Message + "
"); } } async private void ConnectToPeer(Windows.Networking.Proximity.PeerInformation peerInfo) { WriteMessageText("Peer found. Connecting to " + peerInfo.DisplayName + "
"); try { Windows.Networking.Sockets.StreamSocket socket = await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo); WriteMessageText("Connection successful. You may now send messages.
"); SendMessage(socket); } catch (Exception err) { WriteMessageText("Connection failed: " + err.Message + "
"); } requestingPeer = null; } // Click event handler for "Stop" button. private void StopFindingPeersButton_Click(object sender, RoutedEventArgs e) { _started = false; Windows.Networking.Proximity.PeerFinder.Stop(); if (proximitySocket != null) { CloseSocket(); } } // Handle external connection requests. Windows.Networking.Proximity.PeerInformation requestingPeer; private void ConnectionRequested(object sender, Windows.Networking.Proximity.ConnectionRequestedEventArgs e) { requestingPeer = e.PeerInformation; WriteMessageText("Connection requested by " + requestingPeer.DisplayName + ". " + "Click 'Accept Connection' to connect."); } private void AcceptConnectionButton_Click(object sender, RoutedEventArgs e) { if (requestingPeer == null) { WriteMessageText("No peer connection has been requested."); return; } ConnectToPeer(requestingPeer); }
Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName
    AddHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested

    ' If activated from launch or from the background, create a peer connection.
    Dim args = TryCast(e.Parameter, Windows.ApplicationModel.Activation.LaunchActivatedEventArgs)
    If args IsNot Nothing AndAlso args.Kind = Windows.ApplicationModel.Activation.ActivationKind.Launch Then

        If args.Arguments = "Windows.Networking.Proximity.PeerFinder:StreamSocket" Then
            AdvertiseForPeersButton_Click()
        End If
    End If
End Sub

Protected Overrides Sub OnNavigatingFrom(e As Navigation.NavigatingCancelEventArgs)
    If _started Then
        ' Detach the callback handler (there can only be one PeerConnectProgress handler).
        RemoveHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged, AddressOf TriggeredConnectionStateChanged
        ' Detach the incoming connection request event handler.
        RemoveHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested
        Windows.Networking.Proximity.PeerFinder.Stop()
        CloseSocket()
        _started = False
    End If
End Sub

' Write a message to MessageBlock on the UI thread.
Private Async Sub WriteMessageText(message As String, Optional overwrite As Boolean = False)
    Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        Sub()
            If overwrite Then
                MessageBlock.Text = message
            Else
                MessageBlock.Text &= message
            End If
        End Sub)
End Sub

Private _started As Boolean = False

' Click event handler for "Advertise" button.
Private Sub AdvertiseForPeersButton_Click()

    If _started Then
        WriteMessageText("You are already advertising for a connection." & vbCrLf)
        Return
    End If

    Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text

    If ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) =
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) Then

        AddHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged,
            AddressOf TriggeredConnectionStateChanged

        WriteMessageText("You can tap to connect a peer device that is " &
                         "also advertising for a connection." & vbCrLf)
    Else
        WriteMessageText("Tap to connect is not supported." & vbCrLf)
    End If

    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
    End If

    Windows.Networking.Proximity.PeerFinder.Start()
    _started = True
End Sub

Private Sub TriggeredConnectionStateChanged(
    sender As Object,
    e As Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs)

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.PeerFound Then

        WriteMessageText("Peer found. You may now pull your devices out of proximity." & vbCrLf)
    End If

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.Completed Then
        WriteMessageText("Connected. You may now send a message." & vbCrLf)
        SendMessage(e.Socket)
    End If
End Sub

' Click event handler for "Browse" button.
Private Async Sub FindPeersButton_Click()
    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
        Return
    End If

    Try
        Dim peerInfoCollection = Await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync()
        If peerInfoCollection.Count > 0 Then
            ' Connect to first peer found - example only.
            ' In your app, provide the user with a list of available peers.
            ConnectToPeer(peerInfoCollection(0))
        End If
    Catch err As Exception
        WriteMessageText("Error finding peers: " & err.Message & vbCrLf)
    End Try
End Sub

Private Async Sub ConnectToPeer(peerInfo As Windows.Networking.Proximity.PeerInformation)

    WriteMessageText("Peer found. Connecting to " & peerInfo.DisplayName & vbCrLf)
    Try
        Dim socket = Await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo)

        WriteMessageText("Connection successful. You may now send messages." & vbCrLf)
        SendMessage(socket)
    Catch err As Exception
        WriteMessageText("Connection failed: " & err.Message & vbCrLf)
    End Try

    requestingPeer = Nothing
End Sub

' Click event handler for "Stop" button.
Private Sub StopFindingPeersButton_Click()

    _started = False
    Windows.Networking.Proximity.PeerFinder.Stop()
    If proximitySocket IsNot Nothing Then CloseSocket()
End Sub

' Handle external connection requests.
Private requestingPeer As Windows.Networking.Proximity.PeerInformation

Private Sub ConnectionRequested(sender As Object,
    e As Windows.Networking.Proximity.ConnectionRequestedEventArgs)

    requestingPeer = e.PeerInformation

    WriteMessageText("Connection requested by " & requestingPeer.DisplayName & ". " &
        "Click 'Accept Connection' to connect.")
End Sub

Private Sub AcceptConnectionButton_Click()
    If requestingPeer Is Nothing Then
        WriteMessageText("No peer connection has been requested.")
        Return
    End If

    ConnectToPeer(requestingPeer)
End Sub

Remarks

Important

Always set the DisplayName property to a unique value for your app before you call the Start method.

The DisplayName property value is included in the PeerInformation instance that's created when a remote peer calls the FindAllPeersAsync method and finds your computer.

If you don't specify a value for the DisplayName property, the computer name is used.

The maximum length of DisplayName is 50 characters.

See Also

Role Role Role Role

Gets or sets the role of the app in peer-to-peer connections.

public : static PeerRole Role { get; set; }
public static PeerRole Role { get; set; }
Public Static ReadWrite Property Role As PeerRole
var peerRole = Windows.Networking.Proximity.PeerFinder.role;
peerFinder.role = peerRole;
Value
PeerRole PeerRole PeerRole PeerRole

The role of the app in peer-to-peer connections.

Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Examples

// Default to the peer role.
Windows.Networking.Proximity.PeerRole appRole = Windows.Networking.Proximity.PeerRole.Peer;
bool launchedByTap = false;

protected override void OnNavigatedTo(NavigationEventArgs e)
{
    LaunchActivatedEventArgs launchArgs = e.Parameter as LaunchActivatedEventArgs;

    if (launchArgs.Arguments.Contains("Windows.Networking.Proximity.PeerFinder:StreamSocket"))
    {
        launchedByTap = true;

        if (launchArgs.Arguments.Contains("Role=Host"))
        {
            appRole = Windows.Networking.Proximity.PeerRole.Host;
        }
        else if (launchArgs.Arguments.Contains("Role=Client"))
        {
            appRole = Windows.Networking.Proximity.PeerRole.Client;
        }
        else
        {
            appRole = Windows.Networking.Proximity.PeerRole.Peer;
        }
    }
}

bool started = false;

// Click event for "Advertise" button.
void AdvertiseForPeers(object sender, RoutedEventArgs e)
{
    if (!started)
    {
        Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text;

        if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
             Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) ==
             Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered)
        {
            Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged +=
                TriggeredConnectionStateChanged;

            WriteMessageText("You can tap to connect a peer device that is " +
                             "also advertising for a connection.
"); } else { WriteMessageText("Tap to connect is not supported.
"); } if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); } // Set the peer role selected by the user. if (launchedByTap) { Windows.Networking.Proximity.PeerFinder.Role = appRole; } else { switch (GetRoleFromUser()) { case "Peer": Windows.Networking.Proximity.PeerFinder.Role = Windows.Networking.Proximity.PeerRole.Peer; break; case "Host": Windows.Networking.Proximity.PeerFinder.Role = Windows.Networking.Proximity.PeerRole.Host; break; case "Client": Windows.Networking.Proximity.PeerFinder.Role = Windows.Networking.Proximity.PeerRole.Client; break; } } // Set discoveryData property with user supplied text. var discData = GetDiscoveryDataFromUser(); var writer = new Windows.Storage.Streams.DataWriter( new Windows.Storage.Streams.InMemoryRandomAccessStream()); writer.WriteString(discData); Windows.Networking.Proximity.PeerFinder.DiscoveryData = writer.DetachBuffer(); Windows.Networking.Proximity.PeerFinder.Start(); started = true; } } // Write a message to MessageBlock on the UI thread. private Windows.UI.Core.CoreDispatcher messageDispatcher = Window.Current.CoreWindow.Dispatcher; async private void WriteMessageText(string message, bool overwrite = false) { await messageDispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () => { if (overwrite) MessageBlock.Text = message; else MessageBlock.Text += message; }); }
// Default to the peer role.
var appRole = Windows.Networking.Proximity.PeerRole.peer;
var launchedFromTap = false; 

app.onactivated = function (args) {
    if (args.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) {
        Windows.Networking.Proximity.PeerFinder.addEventListener("connectionrequested", connectionRequested);

        // Detect if app launched from a tap.
        if ((args.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) &&
            (args.detail.arguments === "Windows.Networking.Proximity.PeerFinder:StreamSocket")) {

            launchedFromTap = true; 

            if (args.detail.arguments.search("Role=Host") !== -1) { 
                appRole = Windows.Networking.Proximity.PeerRole.host; 
            } 
            else if (args.detail.arguments.search("Role=Client") !== -1) { 
                appRole = Windows.Networking.Proximity.PeerRole.client; 
            } 
            else { 
                appRole = Windows.Networking.Proximity.PeerRole.peer; 
            } 
        } 
    }

    advertiseForPeers(true);

    args.setPromise(WinJS.UI.processAll());
}

var started = false;

// Click event for "Advertise" button.
function advertiseForPeers(launchedFromTap) {
    Windows.Networking.Proximity.PeerFinder.displayName = displayNameTextBox.Text;

    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.triggered) {

        Windows.Networking.Proximity.PeerFinder.addEventListener(
            "triggeredconnectionstatechanged", triggeredConnectionStateChanged);

        id("messageDiv").innerHTML +=
            "You can tap to connect a peer device that is " +
            "also advertising for a connection.<br />";
    } else {
        id("messageDiv").innerHTML +=
            "Tap to connect is not supported.<br />";
    }

    if (!launchedFromTap) {
        if (!(Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
              Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)) {
            id("messageDiv").innerHTML +=
                "Peer discovery using Wi-Fi Direct is not supported.<br />";
        }
    }       

    if (!started) {
        // Set the peer role selected by the user.  
        if (launchedByTap) { 
            Windows.Networking.Proximity.PeerFinder.role = appRole; 
        } 
        else { 
            switch (getRoleFromUser()) { 
                case "peer": 
                    Windows.Networking.Proximity.PeerFinder.role = 
                        Windows.Networking.Proximity.PeerRole.peer; 
                    break; 
                case "host": 
                    Windows.Networking.Proximity.PeerFinder.role = 
                        Windows.Networking.Proximity.PeerRole.host; 
                    break; 
                case "client": 
                    Windows.Networking.Proximity.PeerFinder.role = 
                        Windows.Networking.Proximity.PeerRole.client; 
                    break; 
            } 
        } 

        // Set discoveryData property with user supplied text. 
        var discData = getDiscoveryDataFromUser();
        var writer = Windows.Storage.Streams.DataWriter(
            new Windows.Storage.Streams.InMemoryRandomAccessStream()); 
        writer.writeString(discData); 
        Windows.Networking.Proximity.PeerFinder.discoveryData = 
            writer.detachBuffer(); 

        Windows.Networking.Proximity.PeerFinder.start();
        started = true;
    }
}

Remarks

The Role property is used in multi-peer app connections to identify whether the peer app is the Host or Client, or if the peer app is participating in a two-peer connection as a Peer. For multi-peer app connections, you must set the Role property before calling the Start method. If the Role property is not set, the default is Peer.

In a multi-peer app scenario, the Role identifies the capability of the apps to connect. A Host app can connect to up to five Client apps. Host apps can only discover apps that advertise as Client apps. Client apps can only discover apps that advertise as Host apps. The Peer role identifies a two-app scenario. Therefore, Peer apps can only discover other Peer apps. The same rules apply for peer apps connected using a tap gesture. For example, apps advertising as Host apps can only tap to connect with apps advertising as Client apps.

See Also

SupportedDiscoveryTypes SupportedDiscoveryTypes SupportedDiscoveryTypes SupportedDiscoveryTypes

Gets a value that indicates which discovery options are available to use with the PeerFinder class.

public : static PeerDiscoveryTypes SupportedDiscoveryTypes { get; }
public static PeerDiscoveryTypes SupportedDiscoveryTypes { get; }
Public Static ReadOnly Property SupportedDiscoveryTypes As PeerDiscoveryTypes
var peerDiscoveryTypes = Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes;
Value
PeerDiscoveryTypes PeerDiscoveryTypes PeerDiscoveryTypes PeerDiscoveryTypes

A value that indicates which discovery options are available to use with the PeerFinder class.

Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Examples

var started = false;

// Click event for "Advertise" button.
function advertiseForPeers(launchedFromTap) {
    Windows.Networking.Proximity.PeerFinder.displayName = displayNameTextBox.Text;

    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.triggered) {

        Windows.Networking.Proximity.PeerFinder.addEventListener(
            "triggeredconnectionstatechanged", triggeredConnectionStateChanged);

        id("messageDiv").innerHTML +=
            "You can tap to connect a peer device that is " +
            "also advertising for a connection.<br />";
    } else {
        id("messageDiv").innerHTML +=
      "Tap to connect is not supported.<br />";
    }

    if (!launchedFromTap) {
        if (!(Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
              Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)) {
            id("messageDiv").innerHTML +=
                "Peer discovery using Wi-Fi Direct is not supported.<br />";
        }
    }

    if (!started) {
        Windows.Networking.Proximity.PeerFinder.start();
        started = true;
    }
}

function triggeredConnectionStateChanged(e) {
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.peerFound) {
        id("messageDiv").innerHTML +=
            "Peer found. You may now pull your devices out of proximity.<br />";
    }
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.completed) {
        id("messageDiv").innerHTML += "Connected. You may now send a message.<br />";
        sendMessage(e.socket);
    }
}


// Click event for "Browse" button.
function findPeers() {
    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.browse) {

        Windows.Networking.Proximity.PeerFinder.findAllPeersAsync().done(
    function (peerInfoCollection) {
        if (peerInfoCollection.length > 0) {
            // Connect to first peer found - example only.
            // In your app, provide the user with a list of available peers.
            connectToPeer(peerInfoCollection[0]);
        }
    },
    function (err) {
        id("messageDiv").innerHTML += "Error finding peers: " + err + "<br />";
    });
    } else {
        id("messageDiv").innerHTML +=
  "Peer discovery using Wi-Fi Direct is not supported.<br />";
    }
}

function connectToPeer(peerInfo) {
    id("messageDiv").innerHTML += ("Peer found. Connecting to " + peerInfo.displayName + "<br />");
    Windows.Networking.Proximity.PeerFinder.connectAsync(peerInfo).done(
        function (socket) {
            id("messageDiv").innerHTML += "Connection successful. You may now send messages.<br />";
            sendMessage(socket);
        },
        function (err) {
            id("messageDiv").innerHTML += "Connection failed: " + err + "<br />";
        });

    requestingPeer = null;
}

function stopFindingPeers() {
    Windows.Networking.Proximity.PeerFinder.stop();
    started = false;
    if (proximitySocket != null) { closeSocket(); }
}

// Handle external connection requests.
var requestingPeer;

function connectionRequested(e) {
    id("messageDiv").innerHTML +=
        "Connection requested by " + e.peerInformation.DisplayName + ". " +
        "Click 'Accept Connection' to connect.";
    requestingPeer = e.PeerInformation;
}

function acceptConnection() {
    if (requestingPeer == null) {
        id("messageDiv").innerHTML += "No peer connection has been requested.";
        return;
    }

    connectToPeer(requestingPeer);
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName;
    Windows.Networking.Proximity.PeerFinder.ConnectionRequested += ConnectionRequested;

    // If activated from launch or from the background, create a peer connection.
    var args = e.Parameter as Windows.ApplicationModel.Activation.LaunchActivatedEventArgs;
    if (args != null && args.Kind == Windows.ApplicationModel.Activation.ActivationKind.Launch)
    {
        if (args.Arguments == "Windows.Networking.Proximity.PeerFinder:StreamSocket")
        {
            AdvertiseForPeersButton_Click(null, null);
        }
    }
}

protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
    if (_started)
    {
        // Detach the callback handler (there can only be one PeerConnectProgress handler).
        Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged -= TriggeredConnectionStateChanged;
        // Detach the incoming connection request event handler.
        Windows.Networking.Proximity.PeerFinder.ConnectionRequested -= ConnectionRequested;
        Windows.Networking.Proximity.PeerFinder.Stop();
        CloseSocket();
        _started = false;
    }
}

// Write a message to MessageBlock on the UI thread.
private Windows.UI.Core.CoreDispatcher messageDispatcher = Window.Current.CoreWindow.Dispatcher;

async private void WriteMessageText(string message, bool overwrite = false)
{
    await messageDispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        () =>
        {
            if (overwrite)
                MessageBlock.Text = message;
            else
                MessageBlock.Text += message;
        });
}

bool _started = false;

// Click event handler for "Advertise" button.
private void AdvertiseForPeersButton_Click(object sender, RoutedEventArgs e)
{
    if (_started) 
    {
        WriteMessageText("You are already advertising for a connection.
"); return; } Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text; if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) == Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) { Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged += TriggeredConnectionStateChanged; WriteMessageText("You can tap to connect a peer device that is " + "also advertising for a connection.
"); } else { WriteMessageText("Tap to connect is not supported.
"); } if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); } Windows.Networking.Proximity.PeerFinder.Start(); _started = true; } private void TriggeredConnectionStateChanged( object sender, Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs e) { if (e.State == Windows.Networking.Proximity.TriggeredConnectState.PeerFound) { WriteMessageText("Peer found. You may now pull your devices out of proximity.
"); } if (e.State == Windows.Networking.Proximity.TriggeredConnectState.Completed) { WriteMessageText("Connected. You may now send a message.
"); SendMessage(e.Socket); } } // Click event handler for "Browse" button. async private void FindPeersButton_Click(object sender, RoutedEventArgs e) { if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); return; } try { var peerInfoCollection = await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync(); if (peerInfoCollection.Count > 0) { // Connect to first peer found - example only. // In your app, provide the user with a list of available peers. ConnectToPeer(peerInfoCollection[0]); } } catch (Exception err) { WriteMessageText("Error finding peers: " + err.Message + "
"); } } async private void ConnectToPeer(Windows.Networking.Proximity.PeerInformation peerInfo) { WriteMessageText("Peer found. Connecting to " + peerInfo.DisplayName + "
"); try { Windows.Networking.Sockets.StreamSocket socket = await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo); WriteMessageText("Connection successful. You may now send messages.
"); SendMessage(socket); } catch (Exception err) { WriteMessageText("Connection failed: " + err.Message + "
"); } requestingPeer = null; } // Click event handler for "Stop" button. private void StopFindingPeersButton_Click(object sender, RoutedEventArgs e) { _started = false; Windows.Networking.Proximity.PeerFinder.Stop(); if (proximitySocket != null) { CloseSocket(); } } // Handle external connection requests. Windows.Networking.Proximity.PeerInformation requestingPeer; private void ConnectionRequested(object sender, Windows.Networking.Proximity.ConnectionRequestedEventArgs e) { requestingPeer = e.PeerInformation; WriteMessageText("Connection requested by " + requestingPeer.DisplayName + ". " + "Click 'Accept Connection' to connect."); } private void AcceptConnectionButton_Click(object sender, RoutedEventArgs e) { if (requestingPeer == null) { WriteMessageText("No peer connection has been requested."); return; } ConnectToPeer(requestingPeer); }
Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName
    AddHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested

    ' If activated from launch or from the background, create a peer connection.
    Dim args = TryCast(e.Parameter, Windows.ApplicationModel.Activation.LaunchActivatedEventArgs)
    If args IsNot Nothing AndAlso args.Kind = Windows.ApplicationModel.Activation.ActivationKind.Launch Then

        If args.Arguments = "Windows.Networking.Proximity.PeerFinder:StreamSocket" Then
            AdvertiseForPeersButton_Click()
        End If
    End If
End Sub

Protected Overrides Sub OnNavigatingFrom(e As Navigation.NavigatingCancelEventArgs)
    If _started Then
        ' Detach the callback handler (there can only be one PeerConnectProgress handler).
        RemoveHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged, AddressOf TriggeredConnectionStateChanged
        ' Detach the incoming connection request event handler.
        RemoveHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested
        Windows.Networking.Proximity.PeerFinder.Stop()
        CloseSocket()
        _started = False
    End If
End Sub

' Write a message to MessageBlock on the UI thread.
Private Async Sub WriteMessageText(message As String, Optional overwrite As Boolean = False)
    Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        Sub()
            If overwrite Then
                MessageBlock.Text = message
            Else
                MessageBlock.Text &= message
            End If
        End Sub)
End Sub

Private _started As Boolean = False

' Click event handler for "Advertise" button.
Private Sub AdvertiseForPeersButton_Click()

    If _started Then
        WriteMessageText("You are already advertising for a connection." & vbCrLf)
        Return
    End If

    Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text

    If ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) =
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) Then

        AddHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged,
            AddressOf TriggeredConnectionStateChanged

        WriteMessageText("You can tap to connect a peer device that is " &
                         "also advertising for a connection." & vbCrLf)
    Else
        WriteMessageText("Tap to connect is not supported." & vbCrLf)
    End If

    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
    End If

    Windows.Networking.Proximity.PeerFinder.Start()
    _started = True
End Sub

Private Sub TriggeredConnectionStateChanged(
    sender As Object,
    e As Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs)

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.PeerFound Then

        WriteMessageText("Peer found. You may now pull your devices out of proximity." & vbCrLf)
    End If

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.Completed Then
        WriteMessageText("Connected. You may now send a message." & vbCrLf)
        SendMessage(e.Socket)
    End If
End Sub

' Click event handler for "Browse" button.
Private Async Sub FindPeersButton_Click()
    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
        Return
    End If

    Try
        Dim peerInfoCollection = Await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync()
        If peerInfoCollection.Count > 0 Then
            ' Connect to first peer found - example only.
            ' In your app, provide the user with a list of available peers.
            ConnectToPeer(peerInfoCollection(0))
        End If
    Catch err As Exception
        WriteMessageText("Error finding peers: " & err.Message & vbCrLf)
    End Try
End Sub

Private Async Sub ConnectToPeer(peerInfo As Windows.Networking.Proximity.PeerInformation)

    WriteMessageText("Peer found. Connecting to " & peerInfo.DisplayName & vbCrLf)
    Try
        Dim socket = Await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo)

        WriteMessageText("Connection successful. You may now send messages." & vbCrLf)
        SendMessage(socket)
    Catch err As Exception
        WriteMessageText("Connection failed: " & err.Message & vbCrLf)
    End Try

    requestingPeer = Nothing
End Sub

' Click event handler for "Stop" button.
Private Sub StopFindingPeersButton_Click()

    _started = False
    Windows.Networking.Proximity.PeerFinder.Stop()
    If proximitySocket IsNot Nothing Then CloseSocket()
End Sub

' Handle external connection requests.
Private requestingPeer As Windows.Networking.Proximity.PeerInformation

Private Sub ConnectionRequested(sender As Object,
    e As Windows.Networking.Proximity.ConnectionRequestedEventArgs)

    requestingPeer = e.PeerInformation

    WriteMessageText("Connection requested by " & requestingPeer.DisplayName & ". " &
        "Click 'Accept Connection' to connect.")
End Sub

Private Sub AcceptConnectionButton_Click()
    If requestingPeer Is Nothing Then
        WriteMessageText("No peer connection has been requested.")
        Return
    End If

    ConnectToPeer(requestingPeer)
End Sub
See Also

Methods

ConnectAsync(PeerInformation) ConnectAsync(PeerInformation) ConnectAsync(PeerInformation) ConnectAsync(PeerInformation)

Connects to a peer discovered by a call to the FindAllPeersAsync method.

public : static IAsyncOperation<StreamSocket> ConnectAsync(PeerInformation peerInformation)
public static IAsyncOperation<StreamSocket> ConnectAsync(PeerInformation peerInformation)
Public Static Function ConnectAsync(peerInformation As PeerInformation) As IAsyncOperation( Of StreamSocket )
var iAsyncOperation = Windows.Networking.Proximity.PeerFinder.connectAsync(peerInformation);
Parameters
peerInformation
PeerInformation PeerInformation PeerInformation PeerInformation

A peer information object representing the peer to connect to.

Returns

An asynchronous operation for connecting to a remote peer using the supplied StreamSocket object.

Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Examples

var started = false;

// Click event for "Advertise" button.
function advertiseForPeers(launchedFromTap) {
    Windows.Networking.Proximity.PeerFinder.displayName = displayNameTextBox.Text;

    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.triggered) {

        Windows.Networking.Proximity.PeerFinder.addEventListener(
            "triggeredconnectionstatechanged", triggeredConnectionStateChanged);

        id("messageDiv").innerHTML +=
            "You can tap to connect a peer device that is " +
            "also advertising for a connection.<br />";
    } else {
        id("messageDiv").innerHTML +=
      "Tap to connect is not supported.<br />";
    }

    if (!launchedFromTap) {
        if (!(Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
              Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)) {
            id("messageDiv").innerHTML +=
                "Peer discovery using Wi-Fi Direct is not supported.<br />";
        }
    }

    if (!started) {
        Windows.Networking.Proximity.PeerFinder.start();
        started = true;
    }
}

function triggeredConnectionStateChanged(e) {
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.peerFound) {
        id("messageDiv").innerHTML +=
            "Peer found. You may now pull your devices out of proximity.<br />";
    }
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.completed) {
        id("messageDiv").innerHTML += "Connected. You may now send a message.<br />";
        sendMessage(e.socket);
    }
}


// Click event for "Browse" button.
function findPeers() {
    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.browse) {

        Windows.Networking.Proximity.PeerFinder.findAllPeersAsync().done(
    function (peerInfoCollection) {
        if (peerInfoCollection.length > 0) {
            // Connect to first peer found - example only.
            // In your app, provide the user with a list of available peers.
            connectToPeer(peerInfoCollection[0]);
        }
    },
    function (err) {
        id("messageDiv").innerHTML += "Error finding peers: " + err + "<br />";
    });
    } else {
        id("messageDiv").innerHTML +=
  "Peer discovery using Wi-Fi Direct is not supported.<br />";
    }
}

function connectToPeer(peerInfo) {
    id("messageDiv").innerHTML += ("Peer found. Connecting to " + peerInfo.displayName + "<br />");
    Windows.Networking.Proximity.PeerFinder.connectAsync(peerInfo).done(
        function (socket) {
            id("messageDiv").innerHTML += "Connection successful. You may now send messages.<br />";
            sendMessage(socket);
        },
        function (err) {
            id("messageDiv").innerHTML += "Connection failed: " + err + "<br />";
        });

    requestingPeer = null;
}

function stopFindingPeers() {
    Windows.Networking.Proximity.PeerFinder.stop();
    started = false;
    if (proximitySocket != null) { closeSocket(); }
}

// Handle external connection requests.
var requestingPeer;

function connectionRequested(e) {
    id("messageDiv").innerHTML +=
        "Connection requested by " + e.peerInformation.DisplayName + ". " +
        "Click 'Accept Connection' to connect.";
    requestingPeer = e.PeerInformation;
}

function acceptConnection() {
    if (requestingPeer == null) {
        id("messageDiv").innerHTML += "No peer connection has been requested.";
        return;
    }

    connectToPeer(requestingPeer);
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName;
    Windows.Networking.Proximity.PeerFinder.ConnectionRequested += ConnectionRequested;

    // If activated from launch or from the background, create a peer connection.
    var args = e.Parameter as Windows.ApplicationModel.Activation.LaunchActivatedEventArgs;
    if (args != null && args.Kind == Windows.ApplicationModel.Activation.ActivationKind.Launch)
    {
        if (args.Arguments == "Windows.Networking.Proximity.PeerFinder:StreamSocket")
        {
            AdvertiseForPeersButton_Click(null, null);
        }
    }
}

protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
    if (_started)
    {
        // Detach the callback handler (there can only be one PeerConnectProgress handler).
        Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged -= TriggeredConnectionStateChanged;
        // Detach the incoming connection request event handler.
        Windows.Networking.Proximity.PeerFinder.ConnectionRequested -= ConnectionRequested;
        Windows.Networking.Proximity.PeerFinder.Stop();
        CloseSocket();
        _started = false;
    }
}

// Write a message to MessageBlock on the UI thread.
private Windows.UI.Core.CoreDispatcher messageDispatcher = Window.Current.CoreWindow.Dispatcher;

async private void WriteMessageText(string message, bool overwrite = false)
{
    await messageDispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        () =>
        {
            if (overwrite)
                MessageBlock.Text = message;
            else
                MessageBlock.Text += message;
        });
}

bool _started = false;

// Click event handler for "Advertise" button.
private void AdvertiseForPeersButton_Click(object sender, RoutedEventArgs e)
{
    if (_started) 
    {
        WriteMessageText("You are already advertising for a connection.
"); return; } Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text; if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) == Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) { Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged += TriggeredConnectionStateChanged; WriteMessageText("You can tap to connect a peer device that is " + "also advertising for a connection.
"); } else { WriteMessageText("Tap to connect is not supported.
"); } if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); } Windows.Networking.Proximity.PeerFinder.Start(); _started = true; } private void TriggeredConnectionStateChanged( object sender, Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs e) { if (e.State == Windows.Networking.Proximity.TriggeredConnectState.PeerFound) { WriteMessageText("Peer found. You may now pull your devices out of proximity.
"); } if (e.State == Windows.Networking.Proximity.TriggeredConnectState.Completed) { WriteMessageText("Connected. You may now send a message.
"); SendMessage(e.Socket); } } // Click event handler for "Browse" button. async private void FindPeersButton_Click(object sender, RoutedEventArgs e) { if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); return; } try { var peerInfoCollection = await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync(); if (peerInfoCollection.Count > 0) { // Connect to first peer found - example only. // In your app, provide the user with a list of available peers. ConnectToPeer(peerInfoCollection[0]); } } catch (Exception err) { WriteMessageText("Error finding peers: " + err.Message + "
"); } } async private void ConnectToPeer(Windows.Networking.Proximity.PeerInformation peerInfo) { WriteMessageText("Peer found. Connecting to " + peerInfo.DisplayName + "
"); try { Windows.Networking.Sockets.StreamSocket socket = await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo); WriteMessageText("Connection successful. You may now send messages.
"); SendMessage(socket); } catch (Exception err) { WriteMessageText("Connection failed: " + err.Message + "
"); } requestingPeer = null; } // Click event handler for "Stop" button. private void StopFindingPeersButton_Click(object sender, RoutedEventArgs e) { _started = false; Windows.Networking.Proximity.PeerFinder.Stop(); if (proximitySocket != null) { CloseSocket(); } } // Handle external connection requests. Windows.Networking.Proximity.PeerInformation requestingPeer; private void ConnectionRequested(object sender, Windows.Networking.Proximity.ConnectionRequestedEventArgs e) { requestingPeer = e.PeerInformation; WriteMessageText("Connection requested by " + requestingPeer.DisplayName + ". " + "Click 'Accept Connection' to connect."); } private void AcceptConnectionButton_Click(object sender, RoutedEventArgs e) { if (requestingPeer == null) { WriteMessageText("No peer connection has been requested."); return; } ConnectToPeer(requestingPeer); }
Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName
    AddHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested

    ' If activated from launch or from the background, create a peer connection.
    Dim args = TryCast(e.Parameter, Windows.ApplicationModel.Activation.LaunchActivatedEventArgs)
    If args IsNot Nothing AndAlso args.Kind = Windows.ApplicationModel.Activation.ActivationKind.Launch Then

        If args.Arguments = "Windows.Networking.Proximity.PeerFinder:StreamSocket" Then
            AdvertiseForPeersButton_Click()
        End If
    End If
End Sub

Protected Overrides Sub OnNavigatingFrom(e As Navigation.NavigatingCancelEventArgs)
    If _started Then
        ' Detach the callback handler (there can only be one PeerConnectProgress handler).
        RemoveHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged, AddressOf TriggeredConnectionStateChanged
        ' Detach the incoming connection request event handler.
        RemoveHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested
        Windows.Networking.Proximity.PeerFinder.Stop()
        CloseSocket()
        _started = False
    End If
End Sub

' Write a message to MessageBlock on the UI thread.
Private Async Sub WriteMessageText(message As String, Optional overwrite As Boolean = False)
    Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        Sub()
            If overwrite Then
                MessageBlock.Text = message
            Else
                MessageBlock.Text &= message
            End If
        End Sub)
End Sub

Private _started As Boolean = False

' Click event handler for "Advertise" button.
Private Sub AdvertiseForPeersButton_Click()

    If _started Then
        WriteMessageText("You are already advertising for a connection." & vbCrLf)
        Return
    End If

    Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text

    If ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) =
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) Then

        AddHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged,
            AddressOf TriggeredConnectionStateChanged

        WriteMessageText("You can tap to connect a peer device that is " &
                         "also advertising for a connection." & vbCrLf)
    Else
        WriteMessageText("Tap to connect is not supported." & vbCrLf)
    End If

    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
    End If

    Windows.Networking.Proximity.PeerFinder.Start()
    _started = True
End Sub

Private Sub TriggeredConnectionStateChanged(
    sender As Object,
    e As Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs)

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.PeerFound Then

        WriteMessageText("Peer found. You may now pull your devices out of proximity." & vbCrLf)
    End If

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.Completed Then
        WriteMessageText("Connected. You may now send a message." & vbCrLf)
        SendMessage(e.Socket)
    End If
End Sub

' Click event handler for "Browse" button.
Private Async Sub FindPeersButton_Click()
    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
        Return
    End If

    Try
        Dim peerInfoCollection = Await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync()
        If peerInfoCollection.Count > 0 Then
            ' Connect to first peer found - example only.
            ' In your app, provide the user with a list of available peers.
            ConnectToPeer(peerInfoCollection(0))
        End If
    Catch err As Exception
        WriteMessageText("Error finding peers: " & err.Message & vbCrLf)
    End Try
End Sub

Private Async Sub ConnectToPeer(peerInfo As Windows.Networking.Proximity.PeerInformation)

    WriteMessageText("Peer found. Connecting to " & peerInfo.DisplayName & vbCrLf)
    Try
        Dim socket = Await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo)

        WriteMessageText("Connection successful. You may now send messages." & vbCrLf)
        SendMessage(socket)
    Catch err As Exception
        WriteMessageText("Connection failed: " & err.Message & vbCrLf)
    End Try

    requestingPeer = Nothing
End Sub

' Click event handler for "Stop" button.
Private Sub StopFindingPeersButton_Click()

    _started = False
    Windows.Networking.Proximity.PeerFinder.Stop()
    If proximitySocket IsNot Nothing Then CloseSocket()
End Sub

' Handle external connection requests.
Private requestingPeer As Windows.Networking.Proximity.PeerInformation

Private Sub ConnectionRequested(sender As Object,
    e As Windows.Networking.Proximity.ConnectionRequestedEventArgs)

    requestingPeer = e.PeerInformation

    WriteMessageText("Connection requested by " & requestingPeer.DisplayName & ". " &
        "Click 'Accept Connection' to connect.")
End Sub

Private Sub AcceptConnectionButton_Click()
    If requestingPeer Is Nothing Then
        WriteMessageText("No peer connection has been requested.")
        Return
    End If

    ConnectToPeer(requestingPeer)
End Sub

Remarks

You can obtain an instance of a PeerInformation object for a peer from a call to the FindAllPeersAsync method, or in a handler for the ConnectionRequested event.

If an app calls the ConnectAsync method to create a connection with a peer, the app will no longer advertise for a connection and will not be found by the FindAllPeersAsync method until the app calls the Close method to close the socket connection.

If you open a socket connection by calling the ConnectAsync method, only one socket connection can be open at a time for the computer. If your app, or another app calls the ConnectAsync method, then the existing socket connection will close.

An Access Denied exception will be thrown if you attempt to call ConnectAsync when your app is in the background.

Important

The Proximity APIs do not provide authentication. You should avoid exchanging sensitive data with these APIs.

Windows Phone 8

Wi-Fi Direct is not supported on Windows Phone 8.

See Also

CreateWatcher() CreateWatcher() CreateWatcher() CreateWatcher()

Creates a new instance of a PeerWatcher object for dynamic discovery of peer apps.

public : static PeerWatcher CreateWatcher()
public static PeerWatcher CreateWatcher()
Public Static Function CreateWatcher() As PeerWatcher
var peerWatcher = Windows.Networking.Proximity.PeerFinder.createWatcher();
Returns

An instance of a PeerWatcher object for dynamic discovery of peer apps.

Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
proximity

Remarks

You must first call the Start method before calling the CreateWatcher method.

If you call the CreateWatcher method multiple times, you will receive a reference to the same PeerWatcher instance.

private PeerWatcher _peerWatcher;
private bool _peerWatcherIsRunning = false;
private bool _peerFinderStarted = false;

// The list of peers discovered by the PeerWatcher.
ObservableCollection<PeerInformation> _discoveredPeers = new ObservableCollection<PeerInformation>();
void PeerFinder_StartPeerWatcher(object sender, RoutedEventArgs e)
{
    if (!_peerFinderStarted)
    {
        // PeerFinder must be started first.
        return;
    }

    if (_peerWatcherIsRunning)
    {
        // PeerWatcher is already running.
        return;
    }

    try
    {
        if (_peerWatcher == null)
        {
            _peerWatcher = PeerFinder.CreateWatcher();

            // Add PeerWatcher event handlers. Only add handlers once.
            _peerWatcher.Added += PeerWatcher_Added;
            _peerWatcher.Removed += PeerWatcher_Removed;
            _peerWatcher.Updated += PeerWatcher_Updated;
            _peerWatcher.EnumerationCompleted += PeerWatcher_EnumerationCompleted;
            _peerWatcher.Stopped += PeerWatcher_Stopped;
        }

        // Empty the list of discovered peers.
        _discoveredPeers.Clear();

        // Start the PeerWatcher.
        _peerWatcher.Start();

        _peerWatcherIsRunning = true;
    }
    catch (Exception ex)
    {
        // Exceptions can occur if PeerWatcher.Start is called multiple times or
        // PeerWatcher.Start is called the PeerWatcher is stopping.
    }
}

protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
    if (_peerWatcher != null)
    {
        // Remove event handlers.
        _peerWatcher.Added -= PeerWatcher_Added;
        _peerWatcher.Removed -= PeerWatcher_Removed;
        _peerWatcher.Updated -= PeerWatcher_Updated;
        _peerWatcher.EnumerationCompleted -= PeerWatcher_EnumerationCompleted;
        _peerWatcher.Stopped -= PeerWatcher_Stopped;

        _peerWatcher = null;
    }
}
var _peerWatcher;
var _peerWatcherIsRunning = false;
var _peerFinderStarted = false;

// The list of peers discovered by the PeerWatcher.
var _discoveredPeers = new Array();

function peerFinder_StartPeerWatcher() {
    if (!_peerFinderStarted) {
        // PeerFinder must be started first.
       return;
    }

    if (_peerWatcherIsRunning) {
        // PeerWatcher is already running.
        return;
    }

    try {
        if (!_peerWatcher)
        {
            _peerWatcher = PeerFinder.createWatcher();

            // Add PeerWatcher event handlers. Only add handlers once.
            peerWatcher.addEventListener("added", peerWatcher_Added); 
            peerWatcher.addEventListener("removed", peerWatcher_Removed); 
            peerWatcher.addEventListener("updated",  peerWatcher_Updated); 
            peerWatcher.addEventListener("enumerationcompleted", peerWatcher_EnumerationCompleted); 
            peerWatcher.addEventListener("stopped", peerWatcher_Stopped); 
        }

        // Empty the list of discovered peers.
        _discoveredPeers = new Array();

        // Start the PeerWatcher.
        _peerWatcher.start();

        _peerWatcherIsRunning = true;
    }
    catch (ex)
    {
        // Exceptions can occur if PeerWatcher.Start is called multiple times or
        // PeerWatcher.Start is called the PeerWatcher is stopping.
    }
}
    
function cleanup() {
    if (_peerWatcher) {
        // Remove event handlers.
        peerWatcher.removeEventListener("added", peerWatcher_Added); 
        peerWatcher.removeEventListener("removed", peerWatcher_Removed); 
        peerWatcher.removeEventListener("updated", peerWatcher_Updated); 
        peerWatcher.removeEventListener("enumerationCompleted", peerWatcher_EnumerationCompleted); 
        peerWatcher.removeEventListener("stopped", peerWatcher_Stopped); 

        _peerWatcher = null;
    }
}
var _peerWatcher;
var _peerWatcherIsRunning = false;
var _peerFinderStarted = false;

// The list of peers discovered by the PeerWatcher.
var _discoveredPeers = new Array();

function peerFinder_StartPeerWatcher() {
    if (!_peerFinderStarted) {
        // PeerFinder must be started first.
       return;
    }

    if (_peerWatcherIsRunning) {
        // PeerWatcher is already running.
        return;
    }

    try {
        if (!_peerWatcher)
        {
            _peerWatcher = PeerFinder.createWatcher();

            // Add PeerWatcher event handlers. Only add handlers once.
            peerWatcher.addEventListener("added", peerWatcher_Added); 
            peerWatcher.addEventListener("removed", peerWatcher_Removed); 
            peerWatcher.addEventListener("updated",  peerWatcher_Updated); 
            peerWatcher.addEventListener("enumerationcompleted", peerWatcher_EnumerationCompleted); 
            peerWatcher.addEventListener("stopped", peerWatcher_Stopped); 
        }

        // Empty the list of discovered peers.
        _discoveredPeers = new Array();

        // Start the PeerWatcher.
        _peerWatcher.start();

        _peerWatcherIsRunning = true;
    }
    catch (ex)
    {
        // Exceptions can occur if PeerWatcher.Start is called multiple times or
        // PeerWatcher.Start is called the PeerWatcher is stopping.
    }
}
    
function cleanup() {
    if (_peerWatcher) {
        // Remove event handlers.
        peerWatcher.removeEventListener("added", peerWatcher_Added); 
        peerWatcher.removeEventListener("removed", peerWatcher_Removed); 
        peerWatcher.removeEventListener("updated", peerWatcher_Updated); 
        peerWatcher.removeEventListener("enumerationCompleted", peerWatcher_EnumerationCompleted); 
        peerWatcher.removeEventListener("stopped", peerWatcher_Stopped); 

        _peerWatcher = null;
    }
}
See Also

FindAllPeersAsync() FindAllPeersAsync() FindAllPeersAsync() FindAllPeersAsync()

Asynchronously browses for peer devices that are running the same app within wireless range.

public : static IAsyncOperation<IVectorView<PeerInformation>> FindAllPeersAsync()
public static IAsyncOperation<IReadOnlyList<PeerInformation>> FindAllPeersAsync()
Public Static Function FindAllPeersAsync() As IAsyncOperation<IReadOnlyList<PeerInformation>>( Of IVectorView )
var iAsyncOperation = Windows.Networking.Proximity.PeerFinder.findAllPeersAsync();
Returns
IAsyncOperation<IVectorView<PeerInformation>> IAsyncOperation<IReadOnlyList<PeerInformation>> IAsyncOperation<IReadOnlyList<PeerInformation>> IAsyncOperation<IReadOnlyList<PeerInformation>>

The asynchronous operation for browsing for peer devices that are running your app.

Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Examples

var started = false;

// Click event for "Advertise" button.
function advertiseForPeers(launchedFromTap) {
    Windows.Networking.Proximity.PeerFinder.displayName = displayNameTextBox.Text;

    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.triggered) {

        Windows.Networking.Proximity.PeerFinder.addEventListener(
            "triggeredconnectionstatechanged", triggeredConnectionStateChanged);

        id("messageDiv").innerHTML +=
            "You can tap to connect a peer device that is " +
            "also advertising for a connection.<br />";
    } else {
        id("messageDiv").innerHTML +=
      "Tap to connect is not supported.<br />";
    }

    if (!launchedFromTap) {
        if (!(Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
              Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)) {
            id("messageDiv").innerHTML +=
                "Peer discovery using Wi-Fi Direct is not supported.<br />";
        }
    }

    if (!started) {
        Windows.Networking.Proximity.PeerFinder.start();
        started = true;
    }
}

function triggeredConnectionStateChanged(e) {
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.peerFound) {
        id("messageDiv").innerHTML +=
            "Peer found. You may now pull your devices out of proximity.<br />";
    }
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.completed) {
        id("messageDiv").innerHTML += "Connected. You may now send a message.<br />";
        sendMessage(e.socket);
    }
}


// Click event for "Browse" button.
function findPeers() {
    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.browse) {

        Windows.Networking.Proximity.PeerFinder.findAllPeersAsync().done(
    function (peerInfoCollection) {
        if (peerInfoCollection.length > 0) {
            // Connect to first peer found - example only.
            // In your app, provide the user with a list of available peers.
            connectToPeer(peerInfoCollection[0]);
        }
    },
    function (err) {
        id("messageDiv").innerHTML += "Error finding peers: " + err + "<br />";
    });
    } else {
        id("messageDiv").innerHTML +=
  "Peer discovery using Wi-Fi Direct is not supported.<br />";
    }
}

function connectToPeer(peerInfo) {
    id("messageDiv").innerHTML += ("Peer found. Connecting to " + peerInfo.displayName + "<br />");
    Windows.Networking.Proximity.PeerFinder.connectAsync(peerInfo).done(
        function (socket) {
            id("messageDiv").innerHTML += "Connection successful. You may now send messages.<br />";
            sendMessage(socket);
        },
        function (err) {
            id("messageDiv").innerHTML += "Connection failed: " + err + "<br />";
        });

    requestingPeer = null;
}

function stopFindingPeers() {
    Windows.Networking.Proximity.PeerFinder.stop();
    started = false;
    if (proximitySocket != null) { closeSocket(); }
}

// Handle external connection requests.
var requestingPeer;

function connectionRequested(e) {
    id("messageDiv").innerHTML +=
        "Connection requested by " + e.peerInformation.DisplayName + ". " +
        "Click 'Accept Connection' to connect.";
    requestingPeer = e.PeerInformation;
}

function acceptConnection() {
    if (requestingPeer == null) {
        id("messageDiv").innerHTML += "No peer connection has been requested.";
        return;
    }

    connectToPeer(requestingPeer);
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName;
    Windows.Networking.Proximity.PeerFinder.ConnectionRequested += ConnectionRequested;

    // If activated from launch or from the background, create a peer connection.
    var args = e.Parameter as Windows.ApplicationModel.Activation.LaunchActivatedEventArgs;
    if (args != null && args.Kind == Windows.ApplicationModel.Activation.ActivationKind.Launch)
    {
        if (args.Arguments == "Windows.Networking.Proximity.PeerFinder:StreamSocket")
        {
            AdvertiseForPeersButton_Click(null, null);
        }
    }
}

protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
    if (_started)
    {
        // Detach the callback handler (there can only be one PeerConnectProgress handler).
        Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged -= TriggeredConnectionStateChanged;
        // Detach the incoming connection request event handler.
        Windows.Networking.Proximity.PeerFinder.ConnectionRequested -= ConnectionRequested;
        Windows.Networking.Proximity.PeerFinder.Stop();
        CloseSocket();
        _started = false;
    }
}

// Write a message to MessageBlock on the UI thread.
private Windows.UI.Core.CoreDispatcher messageDispatcher = Window.Current.CoreWindow.Dispatcher;

async private void WriteMessageText(string message, bool overwrite = false)
{
    await messageDispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        () =>
        {
            if (overwrite)
                MessageBlock.Text = message;
            else
                MessageBlock.Text += message;
        });
}

bool _started = false;

// Click event handler for "Advertise" button.
private void AdvertiseForPeersButton_Click(object sender, RoutedEventArgs e)
{
    if (_started) 
    {
        WriteMessageText("You are already advertising for a connection.
"); return; } Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text; if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) == Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) { Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged += TriggeredConnectionStateChanged; WriteMessageText("You can tap to connect a peer device that is " + "also advertising for a connection.
"); } else { WriteMessageText("Tap to connect is not supported.
"); } if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); } Windows.Networking.Proximity.PeerFinder.Start(); _started = true; } private void TriggeredConnectionStateChanged( object sender, Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs e) { if (e.State == Windows.Networking.Proximity.TriggeredConnectState.PeerFound) { WriteMessageText("Peer found. You may now pull your devices out of proximity.
"); } if (e.State == Windows.Networking.Proximity.TriggeredConnectState.Completed) { WriteMessageText("Connected. You may now send a message.
"); SendMessage(e.Socket); } } // Click event handler for "Browse" button. async private void FindPeersButton_Click(object sender, RoutedEventArgs e) { if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); return; } try { var peerInfoCollection = await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync(); if (peerInfoCollection.Count > 0) { // Connect to first peer found - example only. // In your app, provide the user with a list of available peers. ConnectToPeer(peerInfoCollection[0]); } } catch (Exception err) { WriteMessageText("Error finding peers: " + err.Message + "
"); } } async private void ConnectToPeer(Windows.Networking.Proximity.PeerInformation peerInfo) { WriteMessageText("Peer found. Connecting to " + peerInfo.DisplayName + "
"); try { Windows.Networking.Sockets.StreamSocket socket = await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo); WriteMessageText("Connection successful. You may now send messages.
"); SendMessage(socket); } catch (Exception err) { WriteMessageText("Connection failed: " + err.Message + "
"); } requestingPeer = null; } // Click event handler for "Stop" button. private void StopFindingPeersButton_Click(object sender, RoutedEventArgs e) { _started = false; Windows.Networking.Proximity.PeerFinder.Stop(); if (proximitySocket != null) { CloseSocket(); } } // Handle external connection requests. Windows.Networking.Proximity.PeerInformation requestingPeer; private void ConnectionRequested(object sender, Windows.Networking.Proximity.ConnectionRequestedEventArgs e) { requestingPeer = e.PeerInformation; WriteMessageText("Connection requested by " + requestingPeer.DisplayName + ". " + "Click 'Accept Connection' to connect."); } private void AcceptConnectionButton_Click(object sender, RoutedEventArgs e) { if (requestingPeer == null) { WriteMessageText("No peer connection has been requested."); return; } ConnectToPeer(requestingPeer); }
Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName
    AddHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested

    ' If activated from launch or from the background, create a peer connection.
    Dim args = TryCast(e.Parameter, Windows.ApplicationModel.Activation.LaunchActivatedEventArgs)
    If args IsNot Nothing AndAlso args.Kind = Windows.ApplicationModel.Activation.ActivationKind.Launch Then

        If args.Arguments = "Windows.Networking.Proximity.PeerFinder:StreamSocket" Then
            AdvertiseForPeersButton_Click()
        End If
    End If
End Sub

Protected Overrides Sub OnNavigatingFrom(e As Navigation.NavigatingCancelEventArgs)
    If _started Then
        ' Detach the callback handler (there can only be one PeerConnectProgress handler).
        RemoveHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged, AddressOf TriggeredConnectionStateChanged
        ' Detach the incoming connection request event handler.
        RemoveHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested
        Windows.Networking.Proximity.PeerFinder.Stop()
        CloseSocket()
        _started = False
    End If
End Sub

' Write a message to MessageBlock on the UI thread.
Private Async Sub WriteMessageText(message As String, Optional overwrite As Boolean = False)
    Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        Sub()
            If overwrite Then
                MessageBlock.Text = message
            Else
                MessageBlock.Text &= message
            End If
        End Sub)
End Sub

Private _started As Boolean = False

' Click event handler for "Advertise" button.
Private Sub AdvertiseForPeersButton_Click()

    If _started Then
        WriteMessageText("You are already advertising for a connection." & vbCrLf)
        Return
    End If

    Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text

    If ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) =
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) Then

        AddHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged,
            AddressOf TriggeredConnectionStateChanged

        WriteMessageText("You can tap to connect a peer device that is " &
                         "also advertising for a connection." & vbCrLf)
    Else
        WriteMessageText("Tap to connect is not supported." & vbCrLf)
    End If

    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
    End If

    Windows.Networking.Proximity.PeerFinder.Start()
    _started = True
End Sub

Private Sub TriggeredConnectionStateChanged(
    sender As Object,
    e As Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs)

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.PeerFound Then

        WriteMessageText("Peer found. You may now pull your devices out of proximity." & vbCrLf)
    End If

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.Completed Then
        WriteMessageText("Connected. You may now send a message." & vbCrLf)
        SendMessage(e.Socket)
    End If
End Sub

' Click event handler for "Browse" button.
Private Async Sub FindPeersButton_Click()
    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
        Return
    End If

    Try
        Dim peerInfoCollection = Await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync()
        If peerInfoCollection.Count > 0 Then
            ' Connect to first peer found - example only.
            ' In your app, provide the user with a list of available peers.
            ConnectToPeer(peerInfoCollection(0))
        End If
    Catch err As Exception
        WriteMessageText("Error finding peers: " & err.Message & vbCrLf)
    End Try
End Sub

Private Async Sub ConnectToPeer(peerInfo As Windows.Networking.Proximity.PeerInformation)

    WriteMessageText("Peer found. Connecting to " & peerInfo.DisplayName & vbCrLf)
    Try
        Dim socket = Await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo)

        WriteMessageText("Connection successful. You may now send messages." & vbCrLf)
        SendMessage(socket)
    Catch err As Exception
        WriteMessageText("Connection failed: " & err.Message & vbCrLf)
    End Try

    requestingPeer = Nothing
End Sub

' Click event handler for "Stop" button.
Private Sub StopFindingPeersButton_Click()

    _started = False
    Windows.Networking.Proximity.PeerFinder.Stop()
    If proximitySocket IsNot Nothing Then CloseSocket()
End Sub

' Handle external connection requests.
Private requestingPeer As Windows.Networking.Proximity.PeerInformation

Private Sub ConnectionRequested(sender As Object,
    e As Windows.Networking.Proximity.ConnectionRequestedEventArgs)

    requestingPeer = e.PeerInformation

    WriteMessageText("Connection requested by " & requestingPeer.DisplayName & ". " &
        "Click 'Accept Connection' to connect.")
End Sub

Private Sub AcceptConnectionButton_Click()
    If requestingPeer Is Nothing Then
        WriteMessageText("No peer connection has been requested.")
        Return
    End If

    ConnectToPeer(requestingPeer)
End Sub

Remarks

If your app is running on a PC, you can browse for peer PCs that are running your app. Peer discovery in this case takes place over Wi-Fi Direct. If your app is running on a phone, you can browse for peer phones that are running your app. In this case, peer discovery takes place over Bluetooth. Because the transport used for peer discovery differs between PC and phone, your app running on a PC can only find peer PCs and your app running on a phone can only find peer phones.

When the asynchronous browsing operation finishes successfully, it returns a list of peers that are within wireless range. A peer is a device that has an app running in the foreground with a matching app Id. A peer can also have a matching browse Id that's specified as an alternate identity. For more information, see AlternateIdentities.

If an app calls the ConnectAsync method to create a connection with a peer, the app will no longer advertise for a connection and will not be found by the FindAllPeersAsync method until the app calls the Close method to close the socket connection.

You will only find peers where the device is within wireless range and the peer app is running in the foreground. If a peer app is running in the background, proximity does not advertise for peer connections.

As an alternative to the FindAllPeersAsync method, you can dynamically search for peer apps as they are discovered within range using the PeerWatcher object.

Windows Phone 8

Wi-Fi Direct is not supported on Windows Phone 8.

See Also

Start() Start() Start() Start()

Makes an app discoverable to remote peers.

public : static void Start()
public static void Start()
Public Static Function Start() As void
Windows.Networking.Proximity.PeerFinder.start();
Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] ID_CAP_NETWORKING [Windows Phone] ID_CAP_PROXIMITY [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Examples

var started = false;

// Click event for "Advertise" button.
function advertiseForPeers(launchedFromTap) {
    Windows.Networking.Proximity.PeerFinder.displayName = displayNameTextBox.Text;

    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.triggered) {

        Windows.Networking.Proximity.PeerFinder.addEventListener(
            "triggeredconnectionstatechanged", triggeredConnectionStateChanged);

        id("messageDiv").innerHTML +=
            "You can tap to connect a peer device that is " +
            "also advertising for a connection.<br />";
    } else {
        id("messageDiv").innerHTML +=
      "Tap to connect is not supported.<br />";
    }

    if (!launchedFromTap) {
        if (!(Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
              Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)) {
            id("messageDiv").innerHTML +=
                "Peer discovery using Wi-Fi Direct is not supported.<br />";
        }
    }

    if (!started) {
        Windows.Networking.Proximity.PeerFinder.start();
        started = true;
    }
}

function triggeredConnectionStateChanged(e) {
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.peerFound) {
        id("messageDiv").innerHTML +=
            "Peer found. You may now pull your devices out of proximity.<br />";
    }
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.completed) {
        id("messageDiv").innerHTML += "Connected. You may now send a message.<br />";
        sendMessage(e.socket);
    }
}


// Click event for "Browse" button.
function findPeers() {
    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.browse) {

        Windows.Networking.Proximity.PeerFinder.findAllPeersAsync().done(
    function (peerInfoCollection) {
        if (peerInfoCollection.length > 0) {
            // Connect to first peer found - example only.
            // In your app, provide the user with a list of available peers.
            connectToPeer(peerInfoCollection[0]);
        }
    },
    function (err) {
        id("messageDiv").innerHTML += "Error finding peers: " + err + "<br />";
    });
    } else {
        id("messageDiv").innerHTML +=
  "Peer discovery using Wi-Fi Direct is not supported.<br />";
    }
}

function connectToPeer(peerInfo) {
    id("messageDiv").innerHTML += ("Peer found. Connecting to " + peerInfo.displayName + "<br />");
    Windows.Networking.Proximity.PeerFinder.connectAsync(peerInfo).done(
        function (socket) {
            id("messageDiv").innerHTML += "Connection successful. You may now send messages.<br />";
            sendMessage(socket);
        },
        function (err) {
            id("messageDiv").innerHTML += "Connection failed: " + err + "<br />";
        });

    requestingPeer = null;
}

function stopFindingPeers() {
    Windows.Networking.Proximity.PeerFinder.stop();
    started = false;
    if (proximitySocket != null) { closeSocket(); }
}

// Handle external connection requests.
var requestingPeer;

function connectionRequested(e) {
    id("messageDiv").innerHTML +=
        "Connection requested by " + e.peerInformation.DisplayName + ". " +
        "Click 'Accept Connection' to connect.";
    requestingPeer = e.PeerInformation;
}

function acceptConnection() {
    if (requestingPeer == null) {
        id("messageDiv").innerHTML += "No peer connection has been requested.";
        return;
    }

    connectToPeer(requestingPeer);
}
var started = false;

// Click event for "Advertise" button.
function advertiseForPeers(launchedFromTap) {
    Windows.Networking.Proximity.PeerFinder.displayName = displayNameTextBox.Text;

    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.triggered) {

        Windows.Networking.Proximity.PeerFinder.addEventListener(
            "triggeredconnectionstatechanged", triggeredConnectionStateChanged);

        id("messageDiv").innerHTML +=
            "You can tap to connect a peer device that is " +
            "also advertising for a connection.<br />";
    } else {
        id("messageDiv").innerHTML +=
      "Tap to connect is not supported.<br />";
    }

    if (!launchedFromTap) {
        if (!(Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
              Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)) {
            id("messageDiv").innerHTML +=
                "Peer discovery using Wi-Fi Direct is not supported.<br />";
        }
    }

    if (!started) {
        Windows.Networking.Proximity.PeerFinder.start();
        started = true;
    }
}

function triggeredConnectionStateChanged(e) {
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.peerFound) {
        id("messageDiv").innerHTML +=
            "Peer found. You may now pull your devices out of proximity.<br />";
    }
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.completed) {
        id("messageDiv").innerHTML += "Connected. You may now send a message.<br />";
        sendMessage(e.socket);
    }
}


// Click event for "Browse" button.
function findPeers() {
    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.browse) {

        Windows.Networking.Proximity.PeerFinder.findAllPeersAsync().done(
    function (peerInfoCollection) {
        if (peerInfoCollection.length > 0) {
            // Connect to first peer found - example only.
            // In your app, provide the user with a list of available peers.
            connectToPeer(peerInfoCollection[0]);
        }
    },
    function (err) {
        id("messageDiv").innerHTML += "Error finding peers: " + err + "<br />";
    });
    } else {
        id("messageDiv").innerHTML +=
  "Peer discovery using Wi-Fi Direct is not supported.<br />";
    }
}

function connectToPeer(peerInfo) {
    id("messageDiv").innerHTML += ("Peer found. Connecting to " + peerInfo.displayName + "<br />");
    Windows.Networking.Proximity.PeerFinder.connectAsync(peerInfo).done(
        function (socket) {
            id("messageDiv").innerHTML += "Connection successful. You may now send messages.<br />";
            sendMessage(socket);
        },
        function (err) {
            id("messageDiv").innerHTML += "Connection failed: " + err + "<br />";
        });

    requestingPeer = null;
}

function stopFindingPeers() {
    Windows.Networking.Proximity.PeerFinder.stop();
    started = false;
    if (proximitySocket != null) { closeSocket(); }
}

// Handle external connection requests.
var requestingPeer;

function connectionRequested(e) {
    id("messageDiv").innerHTML +=
        "Connection requested by " + e.peerInformation.DisplayName + ". " +
        "Click 'Accept Connection' to connect.";
    requestingPeer = e.PeerInformation;
}

function acceptConnection() {
    if (requestingPeer == null) {
        id("messageDiv").innerHTML += "No peer connection has been requested.";
        return;
    }

    connectToPeer(requestingPeer);
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName;
    Windows.Networking.Proximity.PeerFinder.ConnectionRequested += ConnectionRequested;

    // If activated from launch or from the background, create a peer connection.
    var args = e.Parameter as Windows.ApplicationModel.Activation.LaunchActivatedEventArgs;
    if (args != null && args.Kind == Windows.ApplicationModel.Activation.ActivationKind.Launch)
    {
        if (args.Arguments == "Windows.Networking.Proximity.PeerFinder:StreamSocket")
        {
            AdvertiseForPeersButton_Click(null, null);
        }
    }
}

protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
    if (_started)
    {
        // Detach the callback handler (there can only be one PeerConnectProgress handler).
        Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged -= TriggeredConnectionStateChanged;
        // Detach the incoming connection request event handler.
        Windows.Networking.Proximity.PeerFinder.ConnectionRequested -= ConnectionRequested;
        Windows.Networking.Proximity.PeerFinder.Stop();
        CloseSocket();
        _started = false;
    }
}

// Write a message to MessageBlock on the UI thread.
private Windows.UI.Core.CoreDispatcher messageDispatcher = Window.Current.CoreWindow.Dispatcher;

async private void WriteMessageText(string message, bool overwrite = false)
{
    await messageDispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        () =>
        {
            if (overwrite)
                MessageBlock.Text = message;
            else
                MessageBlock.Text += message;
        });
}

bool _started = false;

// Click event handler for "Advertise" button.
private void AdvertiseForPeersButton_Click(object sender, RoutedEventArgs e)
{
    if (_started) 
    {
        WriteMessageText("You are already advertising for a connection.
"); return; } Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text; if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) == Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) { Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged += TriggeredConnectionStateChanged; WriteMessageText("You can tap to connect a peer device that is " + "also advertising for a connection.
"); } else { WriteMessageText("Tap to connect is not supported.
"); } if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); } Windows.Networking.Proximity.PeerFinder.Start(); _started = true; } private void TriggeredConnectionStateChanged( object sender, Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs e) { if (e.State == Windows.Networking.Proximity.TriggeredConnectState.PeerFound) { WriteMessageText("Peer found. You may now pull your devices out of proximity.
"); } if (e.State == Windows.Networking.Proximity.TriggeredConnectState.Completed) { WriteMessageText("Connected. You may now send a message.
"); SendMessage(e.Socket); } } // Click event handler for "Browse" button. async private void FindPeersButton_Click(object sender, RoutedEventArgs e) { if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); return; } try { var peerInfoCollection = await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync(); if (peerInfoCollection.Count > 0) { // Connect to first peer found - example only. // In your app, provide the user with a list of available peers. ConnectToPeer(peerInfoCollection[0]); } } catch (Exception err) { WriteMessageText("Error finding peers: " + err.Message + "
"); } } async private void ConnectToPeer(Windows.Networking.Proximity.PeerInformation peerInfo) { WriteMessageText("Peer found. Connecting to " + peerInfo.DisplayName + "
"); try { Windows.Networking.Sockets.StreamSocket socket = await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo); WriteMessageText("Connection successful. You may now send messages.
"); SendMessage(socket); } catch (Exception err) { WriteMessageText("Connection failed: " + err.Message + "
"); } requestingPeer = null; } // Click event handler for "Stop" button. private void StopFindingPeersButton_Click(object sender, RoutedEventArgs e) { _started = false; Windows.Networking.Proximity.PeerFinder.Stop(); if (proximitySocket != null) { CloseSocket(); } } // Handle external connection requests. Windows.Networking.Proximity.PeerInformation requestingPeer; private void ConnectionRequested(object sender, Windows.Networking.Proximity.ConnectionRequestedEventArgs e) { requestingPeer = e.PeerInformation; WriteMessageText("Connection requested by " + requestingPeer.DisplayName + ". " + "Click 'Accept Connection' to connect."); } private void AcceptConnectionButton_Click(object sender, RoutedEventArgs e) { if (requestingPeer == null) { WriteMessageText("No peer connection has been requested."); return; } ConnectToPeer(requestingPeer); }
Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName
    AddHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested

    ' If activated from launch or from the background, create a peer connection.
    Dim args = TryCast(e.Parameter, Windows.ApplicationModel.Activation.LaunchActivatedEventArgs)
    If args IsNot Nothing AndAlso args.Kind = Windows.ApplicationModel.Activation.ActivationKind.Launch Then

        If args.Arguments = "Windows.Networking.Proximity.PeerFinder:StreamSocket" Then
            AdvertiseForPeersButton_Click()
        End If
    End If
End Sub

Protected Overrides Sub OnNavigatingFrom(e As Navigation.NavigatingCancelEventArgs)
    If _started Then
        ' Detach the callback handler (there can only be one PeerConnectProgress handler).
        RemoveHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged, AddressOf TriggeredConnectionStateChanged
        ' Detach the incoming connection request event handler.
        RemoveHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested
        Windows.Networking.Proximity.PeerFinder.Stop()
        CloseSocket()
        _started = False
    End If
End Sub

' Write a message to MessageBlock on the UI thread.
Private Async Sub WriteMessageText(message As String, Optional overwrite As Boolean = False)
    Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        Sub()
            If overwrite Then
                MessageBlock.Text = message
            Else
                MessageBlock.Text &= message
            End If
        End Sub)
End Sub

Private _started As Boolean = False

' Click event handler for "Advertise" button.
Private Sub AdvertiseForPeersButton_Click()

    If _started Then
        WriteMessageText("You are already advertising for a connection." & vbCrLf)
        Return
    End If

    Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text

    If ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) =
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) Then

        AddHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged,
            AddressOf TriggeredConnectionStateChanged

        WriteMessageText("You can tap to connect a peer device that is " &
                         "also advertising for a connection." & vbCrLf)
    Else
        WriteMessageText("Tap to connect is not supported." & vbCrLf)
    End If

    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
    End If

    Windows.Networking.Proximity.PeerFinder.Start()
    _started = True
End Sub

Private Sub TriggeredConnectionStateChanged(
    sender As Object,
    e As Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs)

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.PeerFound Then

        WriteMessageText("Peer found. You may now pull your devices out of proximity." & vbCrLf)
    End If

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.Completed Then
        WriteMessageText("Connected. You may now send a message." & vbCrLf)
        SendMessage(e.Socket)
    End If
End Sub

' Click event handler for "Browse" button.
Private Async Sub FindPeersButton_Click()
    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
        Return
    End If

    Try
        Dim peerInfoCollection = Await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync()
        If peerInfoCollection.Count > 0 Then
            ' Connect to first peer found - example only.
            ' In your app, provide the user with a list of available peers.
            ConnectToPeer(peerInfoCollection(0))
        End If
    Catch err As Exception
        WriteMessageText("Error finding peers: " & err.Message & vbCrLf)
    End Try
End Sub

Private Async Sub ConnectToPeer(peerInfo As Windows.Networking.Proximity.PeerInformation)

    WriteMessageText("Peer found. Connecting to " & peerInfo.DisplayName & vbCrLf)
    Try
        Dim socket = Await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo)

        WriteMessageText("Connection successful. You may now send messages." & vbCrLf)
        SendMessage(socket)
    Catch err As Exception
        WriteMessageText("Connection failed: " & err.Message & vbCrLf)
    End Try

    requestingPeer = Nothing
End Sub

' Click event handler for "Stop" button.
Private Sub StopFindingPeersButton_Click()

    _started = False
    Windows.Networking.Proximity.PeerFinder.Stop()
    If proximitySocket IsNot Nothing Then CloseSocket()
End Sub

' Handle external connection requests.
Private requestingPeer As Windows.Networking.Proximity.PeerInformation

Private Sub ConnectionRequested(sender As Object,
    e As Windows.Networking.Proximity.ConnectionRequestedEventArgs)

    requestingPeer = e.PeerInformation

    WriteMessageText("Connection requested by " & requestingPeer.DisplayName & ". " &
        "Click 'Accept Connection' to connect.")
End Sub

Private Sub AcceptConnectionButton_Click()
    If requestingPeer Is Nothing Then
        WriteMessageText("No peer connection has been requested.")
        Return
    End If

    ConnectToPeer(requestingPeer)
End Sub
protected override void OnNavigatedTo(NavigationEventArgs e)
{
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName;
    Windows.Networking.Proximity.PeerFinder.ConnectionRequested += ConnectionRequested;

    // If activated from launch or from the background, create a peer connection.
    var args = e.Parameter as Windows.ApplicationModel.Activation.LaunchActivatedEventArgs;
    if (args != null && args.Kind == Windows.ApplicationModel.Activation.ActivationKind.Launch)
    {
        if (args.Arguments == "Windows.Networking.Proximity.PeerFinder:StreamSocket")
        {
            AdvertiseForPeersButton_Click(null, null);
        }
    }
}

protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
    if (_started)
    {
        // Detach the callback handler (there can only be one PeerConnectProgress handler).
        Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged -= TriggeredConnectionStateChanged;
        // Detach the incoming connection request event handler.
        Windows.Networking.Proximity.PeerFinder.ConnectionRequested -= ConnectionRequested;
        Windows.Networking.Proximity.PeerFinder.Stop();
        CloseSocket();
        _started = false;
    }
}

// Write a message to MessageBlock on the UI thread.
private Windows.UI.Core.CoreDispatcher messageDispatcher = Window.Current.CoreWindow.Dispatcher;

async private void WriteMessageText(string message, bool overwrite = false)
{
    await messageDispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        () =>
        {
            if (overwrite)
                MessageBlock.Text = message;
            else
                MessageBlock.Text += message;
        });
}

bool _started = false;

// Click event handler for "Advertise" button.
private void AdvertiseForPeersButton_Click(object sender, RoutedEventArgs e)
{
    if (_started) 
    {
        WriteMessageText("You are already advertising for a connection.
"); return; } Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text; if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) == Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) { Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged += TriggeredConnectionStateChanged; WriteMessageText("You can tap to connect a peer device that is " + "also advertising for a connection.
"); } else { WriteMessageText("Tap to connect is not supported.
"); } if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); } Windows.Networking.Proximity.PeerFinder.Start(); _started = true; } private void TriggeredConnectionStateChanged( object sender, Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs e) { if (e.State == Windows.Networking.Proximity.TriggeredConnectState.PeerFound) { WriteMessageText("Peer found. You may now pull your devices out of proximity.
"); } if (e.State == Windows.Networking.Proximity.TriggeredConnectState.Completed) { WriteMessageText("Connected. You may now send a message.
"); SendMessage(e.Socket); } } // Click event handler for "Browse" button. async private void FindPeersButton_Click(object sender, RoutedEventArgs e) { if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); return; } try { var peerInfoCollection = await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync(); if (peerInfoCollection.Count > 0) { // Connect to first peer found - example only. // In your app, provide the user with a list of available peers. ConnectToPeer(peerInfoCollection[0]); } } catch (Exception err) { WriteMessageText("Error finding peers: " + err.Message + "
"); } } async private void ConnectToPeer(Windows.Networking.Proximity.PeerInformation peerInfo) { WriteMessageText("Peer found. Connecting to " + peerInfo.DisplayName + "
"); try { Windows.Networking.Sockets.StreamSocket socket = await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo); WriteMessageText("Connection successful. You may now send messages.
"); SendMessage(socket); } catch (Exception err) { WriteMessageText("Connection failed: " + err.Message + "
"); } requestingPeer = null; } // Click event handler for "Stop" button. private void StopFindingPeersButton_Click(object sender, RoutedEventArgs e) { _started = false; Windows.Networking.Proximity.PeerFinder.Stop(); if (proximitySocket != null) { CloseSocket(); } } // Handle external connection requests. Windows.Networking.Proximity.PeerInformation requestingPeer; private void ConnectionRequested(object sender, Windows.Networking.Proximity.ConnectionRequestedEventArgs e) { requestingPeer = e.PeerInformation; WriteMessageText("Connection requested by " + requestingPeer.DisplayName + ". " + "Click 'Accept Connection' to connect."); } private void AcceptConnectionButton_Click(object sender, RoutedEventArgs e) { if (requestingPeer == null) { WriteMessageText("No peer connection has been requested."); return; } ConnectToPeer(requestingPeer); }
Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName
    AddHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested

    ' If activated from launch or from the background, create a peer connection.
    Dim args = TryCast(e.Parameter, Windows.ApplicationModel.Activation.LaunchActivatedEventArgs)
    If args IsNot Nothing AndAlso args.Kind = Windows.ApplicationModel.Activation.ActivationKind.Launch Then

        If args.Arguments = "Windows.Networking.Proximity.PeerFinder:StreamSocket" Then
            AdvertiseForPeersButton_Click()
        End If
    End If
End Sub

Protected Overrides Sub OnNavigatingFrom(e As Navigation.NavigatingCancelEventArgs)
    If _started Then
        ' Detach the callback handler (there can only be one PeerConnectProgress handler).
        RemoveHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged, AddressOf TriggeredConnectionStateChanged
        ' Detach the incoming connection request event handler.
        RemoveHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested
        Windows.Networking.Proximity.PeerFinder.Stop()
        CloseSocket()
        _started = False
    End If
End Sub

' Write a message to MessageBlock on the UI thread.
Private Async Sub WriteMessageText(message As String, Optional overwrite As Boolean = False)
    Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        Sub()
            If overwrite Then
                MessageBlock.Text = message
            Else
                MessageBlock.Text &= message
            End If
        End Sub)
End Sub

Private _started As Boolean = False

' Click event handler for "Advertise" button.
Private Sub AdvertiseForPeersButton_Click()

    If _started Then
        WriteMessageText("You are already advertising for a connection." & vbCrLf)
        Return
    End If

    Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text

    If ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) =
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) Then

        AddHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged,
            AddressOf TriggeredConnectionStateChanged

        WriteMessageText("You can tap to connect a peer device that is " &
                         "also advertising for a connection." & vbCrLf)
    Else
        WriteMessageText("Tap to connect is not supported." & vbCrLf)
    End If

    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
    End If

    Windows.Networking.Proximity.PeerFinder.Start()
    _started = True
End Sub

Private Sub TriggeredConnectionStateChanged(
    sender As Object,
    e As Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs)

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.PeerFound Then

        WriteMessageText("Peer found. You may now pull your devices out of proximity." & vbCrLf)
    End If

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.Completed Then
        WriteMessageText("Connected. You may now send a message." & vbCrLf)
        SendMessage(e.Socket)
    End If
End Sub

' Click event handler for "Browse" button.
Private Async Sub FindPeersButton_Click()
    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
        Return
    End If

    Try
        Dim peerInfoCollection = Await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync()
        If peerInfoCollection.Count > 0 Then
            ' Connect to first peer found - example only.
            ' In your app, provide the user with a list of available peers.
            ConnectToPeer(peerInfoCollection(0))
        End If
    Catch err As Exception
        WriteMessageText("Error finding peers: " & err.Message & vbCrLf)
    End Try
End Sub

Private Async Sub ConnectToPeer(peerInfo As Windows.Networking.Proximity.PeerInformation)

    WriteMessageText("Peer found. Connecting to " & peerInfo.DisplayName & vbCrLf)
    Try
        Dim socket = Await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo)

        WriteMessageText("Connection successful. You may now send messages." & vbCrLf)
        SendMessage(socket)
    Catch err As Exception
        WriteMessageText("Connection failed: " & err.Message & vbCrLf)
    End Try

    requestingPeer = Nothing
End Sub

' Click event handler for "Stop" button.
Private Sub StopFindingPeersButton_Click()

    _started = False
    Windows.Networking.Proximity.PeerFinder.Stop()
    If proximitySocket IsNot Nothing Then CloseSocket()
End Sub

' Handle external connection requests.
Private requestingPeer As Windows.Networking.Proximity.PeerInformation

Private Sub ConnectionRequested(sender As Object,
    e As Windows.Networking.Proximity.ConnectionRequestedEventArgs)

    requestingPeer = e.PeerInformation

    WriteMessageText("Connection requested by " & requestingPeer.DisplayName & ". " &
        "Click 'Accept Connection' to connect.")
End Sub

Private Sub AcceptConnectionButton_Click()
    If requestingPeer Is Nothing Then
        WriteMessageText("No peer connection has been requested.")
        Return
    End If

    ConnectToPeer(requestingPeer)
End Sub

Remarks

You can call the Start method to begin the process of finding a peer app and to make your app discoverable to remote peers that call the FindAllPeersAsync method. A peer is a device that has an app running in the foreground with a matching AppId. A peer can also have a matching Browse Id that's specified as an alternate identity. For more information, see AlternateIdentities.

You can connect to only one peer at a time if your app is in the peer or client role. If your app is in the host role, you can connect up to 5 clients at a time.

When an app is activated by tapping a nearby device, the activation parameters indicate whether the PeerFinder should be started or if the app was launched with activation arguments. The format of the activation parameters is "Windows.Networking.Proximity.PeerFinder:StreamSocket Role=<Host|Client>". For more information, see the "Activating apps using Proximity" section of Supporting Proximity and Tapping.

Important

Always set the DisplayName property to a unique value for your app before you call the Start method.

Windows Phone 8

Wi-Fi Direct is not supported on Windows Phone 8.

See Also

Start(String) Start(String) Start(String) Start(String)

Makes an app discoverable to remote peers.

public : static void Start(Platform::String peerMessage)
public static void Start(String peerMessage)
Public Static Function Start(peerMessage As String) As void
Windows.Networking.Proximity.PeerFinder.start(peerMessage);
Parameters
peerMessage
Platform::String String String String

The message to deliver to the proximate device.

Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Remarks

You can call the Start method to begin the process of finding a peer app and to make your app discoverable to remote peers that call the FindAllPeersAsync method. A peer is a device that has an app running in the foreground with a matching AppId. A peer can also have a matching Browse Id that's specified as an alternate identity. For more information, see AlternateIdentities.

You can use this overload of the Start method to send a message to a peer app that will be passed as an app activation argument.

You can connect to only one peer at a time if your app is in the peer or client role. If your app is in the host role, you can connect up to 5 clients at a time.

When an app is activated by tapping a nearby device, the activation parameters indicate whether the PeerFinder should be started or if the app was launched with activation arguments. The format of the activation parameters is "Windows.Networking.Proximity.PeerFinder:StreamSocket Role=<Host|Client>". For more information, see the "Activating apps using Proximity" section of Supporting Proximity and Tapping.

Important

Always set the DisplayName property to a unique value for your app before you call the Start method.

Windows Phone 8

Wi-Fi Direct is not supported on Windows Phone 8.

See Also

Stop() Stop() Stop() Stop()

Stops advertising for a peer connection.

public : static void Stop()
public static void Stop()
Public Static Function Stop() As void
Windows.Networking.Proximity.PeerFinder.stop();
Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Examples

var started = false;

// Click event for "Advertise" button.
function advertiseForPeers(launchedFromTap) {
    Windows.Networking.Proximity.PeerFinder.displayName = displayNameTextBox.Text;

    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.triggered) {

        Windows.Networking.Proximity.PeerFinder.addEventListener(
            "triggeredconnectionstatechanged", triggeredConnectionStateChanged);

        id("messageDiv").innerHTML +=
            "You can tap to connect a peer device that is " +
            "also advertising for a connection.<br />";
    } else {
        id("messageDiv").innerHTML +=
      "Tap to connect is not supported.<br />";
    }

    if (!launchedFromTap) {
        if (!(Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
              Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)) {
            id("messageDiv").innerHTML +=
                "Peer discovery using Wi-Fi Direct is not supported.<br />";
        }
    }

    if (!started) {
        Windows.Networking.Proximity.PeerFinder.start();
        started = true;
    }
}

function triggeredConnectionStateChanged(e) {
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.peerFound) {
        id("messageDiv").innerHTML +=
            "Peer found. You may now pull your devices out of proximity.<br />";
    }
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.completed) {
        id("messageDiv").innerHTML += "Connected. You may now send a message.<br />";
        sendMessage(e.socket);
    }
}


// Click event for "Browse" button.
function findPeers() {
    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.browse) {

        Windows.Networking.Proximity.PeerFinder.findAllPeersAsync().done(
    function (peerInfoCollection) {
        if (peerInfoCollection.length > 0) {
            // Connect to first peer found - example only.
            // In your app, provide the user with a list of available peers.
            connectToPeer(peerInfoCollection[0]);
        }
    },
    function (err) {
        id("messageDiv").innerHTML += "Error finding peers: " + err + "<br />";
    });
    } else {
        id("messageDiv").innerHTML +=
  "Peer discovery using Wi-Fi Direct is not supported.<br />";
    }
}

function connectToPeer(peerInfo) {
    id("messageDiv").innerHTML += ("Peer found. Connecting to " + peerInfo.displayName + "<br />");
    Windows.Networking.Proximity.PeerFinder.connectAsync(peerInfo).done(
        function (socket) {
            id("messageDiv").innerHTML += "Connection successful. You may now send messages.<br />";
            sendMessage(socket);
        },
        function (err) {
            id("messageDiv").innerHTML += "Connection failed: " + err + "<br />";
        });

    requestingPeer = null;
}

function stopFindingPeers() {
    Windows.Networking.Proximity.PeerFinder.stop();
    started = false;
    if (proximitySocket != null) { closeSocket(); }
}

// Handle external connection requests.
var requestingPeer;

function connectionRequested(e) {
    id("messageDiv").innerHTML +=
        "Connection requested by " + e.peerInformation.DisplayName + ". " +
        "Click 'Accept Connection' to connect.";
    requestingPeer = e.PeerInformation;
}

function acceptConnection() {
    if (requestingPeer == null) {
        id("messageDiv").innerHTML += "No peer connection has been requested.";
        return;
    }

    connectToPeer(requestingPeer);
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName;
    Windows.Networking.Proximity.PeerFinder.ConnectionRequested += ConnectionRequested;

    // If activated from launch or from the background, create a peer connection.
    var args = e.Parameter as Windows.ApplicationModel.Activation.LaunchActivatedEventArgs;
    if (args != null && args.Kind == Windows.ApplicationModel.Activation.ActivationKind.Launch)
    {
        if (args.Arguments == "Windows.Networking.Proximity.PeerFinder:StreamSocket")
        {
            AdvertiseForPeersButton_Click(null, null);
        }
    }
}

protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
    if (_started)
    {
        // Detach the callback handler (there can only be one PeerConnectProgress handler).
        Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged -= TriggeredConnectionStateChanged;
        // Detach the incoming connection request event handler.
        Windows.Networking.Proximity.PeerFinder.ConnectionRequested -= ConnectionRequested;
        Windows.Networking.Proximity.PeerFinder.Stop();
        CloseSocket();
        _started = false;
    }
}

// Write a message to MessageBlock on the UI thread.
private Windows.UI.Core.CoreDispatcher messageDispatcher = Window.Current.CoreWindow.Dispatcher;

async private void WriteMessageText(string message, bool overwrite = false)
{
    await messageDispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        () =>
        {
            if (overwrite)
                MessageBlock.Text = message;
            else
                MessageBlock.Text += message;
        });
}

bool _started = false;

// Click event handler for "Advertise" button.
private void AdvertiseForPeersButton_Click(object sender, RoutedEventArgs e)
{
    if (_started) 
    {
        WriteMessageText("You are already advertising for a connection.
"); return; } Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text; if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) == Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) { Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged += TriggeredConnectionStateChanged; WriteMessageText("You can tap to connect a peer device that is " + "also advertising for a connection.
"); } else { WriteMessageText("Tap to connect is not supported.
"); } if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); } Windows.Networking.Proximity.PeerFinder.Start(); _started = true; } private void TriggeredConnectionStateChanged( object sender, Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs e) { if (e.State == Windows.Networking.Proximity.TriggeredConnectState.PeerFound) { WriteMessageText("Peer found. You may now pull your devices out of proximity.
"); } if (e.State == Windows.Networking.Proximity.TriggeredConnectState.Completed) { WriteMessageText("Connected. You may now send a message.
"); SendMessage(e.Socket); } } // Click event handler for "Browse" button. async private void FindPeersButton_Click(object sender, RoutedEventArgs e) { if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); return; } try { var peerInfoCollection = await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync(); if (peerInfoCollection.Count > 0) { // Connect to first peer found - example only. // In your app, provide the user with a list of available peers. ConnectToPeer(peerInfoCollection[0]); } } catch (Exception err) { WriteMessageText("Error finding peers: " + err.Message + "
"); } } async private void ConnectToPeer(Windows.Networking.Proximity.PeerInformation peerInfo) { WriteMessageText("Peer found. Connecting to " + peerInfo.DisplayName + "
"); try { Windows.Networking.Sockets.StreamSocket socket = await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo); WriteMessageText("Connection successful. You may now send messages.
"); SendMessage(socket); } catch (Exception err) { WriteMessageText("Connection failed: " + err.Message + "
"); } requestingPeer = null; } // Click event handler for "Stop" button. private void StopFindingPeersButton_Click(object sender, RoutedEventArgs e) { _started = false; Windows.Networking.Proximity.PeerFinder.Stop(); if (proximitySocket != null) { CloseSocket(); } } // Handle external connection requests. Windows.Networking.Proximity.PeerInformation requestingPeer; private void ConnectionRequested(object sender, Windows.Networking.Proximity.ConnectionRequestedEventArgs e) { requestingPeer = e.PeerInformation; WriteMessageText("Connection requested by " + requestingPeer.DisplayName + ". " + "Click 'Accept Connection' to connect."); } private void AcceptConnectionButton_Click(object sender, RoutedEventArgs e) { if (requestingPeer == null) { WriteMessageText("No peer connection has been requested."); return; } ConnectToPeer(requestingPeer); }
Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName
    AddHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested

    ' If activated from launch or from the background, create a peer connection.
    Dim args = TryCast(e.Parameter, Windows.ApplicationModel.Activation.LaunchActivatedEventArgs)
    If args IsNot Nothing AndAlso args.Kind = Windows.ApplicationModel.Activation.ActivationKind.Launch Then

        If args.Arguments = "Windows.Networking.Proximity.PeerFinder:StreamSocket" Then
            AdvertiseForPeersButton_Click()
        End If
    End If
End Sub

Protected Overrides Sub OnNavigatingFrom(e As Navigation.NavigatingCancelEventArgs)
    If _started Then
        ' Detach the callback handler (there can only be one PeerConnectProgress handler).
        RemoveHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged, AddressOf TriggeredConnectionStateChanged
        ' Detach the incoming connection request event handler.
        RemoveHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested
        Windows.Networking.Proximity.PeerFinder.Stop()
        CloseSocket()
        _started = False
    End If
End Sub

' Write a message to MessageBlock on the UI thread.
Private Async Sub WriteMessageText(message As String, Optional overwrite As Boolean = False)
    Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        Sub()
            If overwrite Then
                MessageBlock.Text = message
            Else
                MessageBlock.Text &= message
            End If
        End Sub)
End Sub

Private _started As Boolean = False

' Click event handler for "Advertise" button.
Private Sub AdvertiseForPeersButton_Click()

    If _started Then
        WriteMessageText("You are already advertising for a connection." & vbCrLf)
        Return
    End If

    Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text

    If ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) =
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) Then

        AddHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged,
            AddressOf TriggeredConnectionStateChanged

        WriteMessageText("You can tap to connect a peer device that is " &
                         "also advertising for a connection." & vbCrLf)
    Else
        WriteMessageText("Tap to connect is not supported." & vbCrLf)
    End If

    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
    End If

    Windows.Networking.Proximity.PeerFinder.Start()
    _started = True
End Sub

Private Sub TriggeredConnectionStateChanged(
    sender As Object,
    e As Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs)

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.PeerFound Then

        WriteMessageText("Peer found. You may now pull your devices out of proximity." & vbCrLf)
    End If

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.Completed Then
        WriteMessageText("Connected. You may now send a message." & vbCrLf)
        SendMessage(e.Socket)
    End If
End Sub

' Click event handler for "Browse" button.
Private Async Sub FindPeersButton_Click()
    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
        Return
    End If

    Try
        Dim peerInfoCollection = Await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync()
        If peerInfoCollection.Count > 0 Then
            ' Connect to first peer found - example only.
            ' In your app, provide the user with a list of available peers.
            ConnectToPeer(peerInfoCollection(0))
        End If
    Catch err As Exception
        WriteMessageText("Error finding peers: " & err.Message & vbCrLf)
    End Try
End Sub

Private Async Sub ConnectToPeer(peerInfo As Windows.Networking.Proximity.PeerInformation)

    WriteMessageText("Peer found. Connecting to " & peerInfo.DisplayName & vbCrLf)
    Try
        Dim socket = Await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo)

        WriteMessageText("Connection successful. You may now send messages." & vbCrLf)
        SendMessage(socket)
    Catch err As Exception
        WriteMessageText("Connection failed: " & err.Message & vbCrLf)
    End Try

    requestingPeer = Nothing
End Sub

' Click event handler for "Stop" button.
Private Sub StopFindingPeersButton_Click()

    _started = False
    Windows.Networking.Proximity.PeerFinder.Stop()
    If proximitySocket IsNot Nothing Then CloseSocket()
End Sub

' Handle external connection requests.
Private requestingPeer As Windows.Networking.Proximity.PeerInformation

Private Sub ConnectionRequested(sender As Object,
    e As Windows.Networking.Proximity.ConnectionRequestedEventArgs)

    requestingPeer = e.PeerInformation

    WriteMessageText("Connection requested by " & requestingPeer.DisplayName & ". " &
        "Click 'Accept Connection' to connect.")
End Sub

Private Sub AcceptConnectionButton_Click()
    If requestingPeer Is Nothing Then
        WriteMessageText("No peer connection has been requested.")
        Return
    End If

    ConnectToPeer(requestingPeer)
End Sub

Remarks

You can call the Stop method to stop the PeerFinder when you no longer want to advertise for or accept new triggered (tapped) or browsed connections. Stop does not close an existing connection. However, the Stop method will cancel outstanding calls to the ConnectAsync method and triggered connection requests. The Stop method does not wait for the cancellation to complete.

See Also

Events

ConnectionRequested ConnectionRequested ConnectionRequested ConnectionRequested

Occurs when a remote peer requests a connection using the ConnectAsync method.

public : event TypedEventHandler ConnectionRequested<Platform::Object,  ConnectionRequestedEventArgs>
public event TypedEventHandler ConnectionRequested<object,  ConnectionRequestedEventArgs>
Public Event TypedEventHandler ConnectionRequested( Of ( Of object ), ( Of  ConnectionRequestedEventArgs ))
function onConnectionRequested(eventArgs){/* Your code */}


peerFinder.addEventListener("connectionRequested", onConnectionRequested);
peerFinder.removeEventListener("connectionRequested", onConnectionRequested);
Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Examples

var started = false;

// Click event for "Advertise" button.
function advertiseForPeers(launchedFromTap) {
    Windows.Networking.Proximity.PeerFinder.displayName = displayNameTextBox.Text;

    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.triggered) {

        Windows.Networking.Proximity.PeerFinder.addEventListener(
            "triggeredconnectionstatechanged", triggeredConnectionStateChanged);

        id("messageDiv").innerHTML +=
            "You can tap to connect a peer device that is " +
            "also advertising for a connection.<br />";
    } else {
        id("messageDiv").innerHTML +=
      "Tap to connect is not supported.<br />";
    }

    if (!launchedFromTap) {
        if (!(Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
              Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)) {
            id("messageDiv").innerHTML +=
                "Peer discovery using Wi-Fi Direct is not supported.<br />";
        }
    }

    if (!started) {
        Windows.Networking.Proximity.PeerFinder.start();
        started = true;
    }
}

function triggeredConnectionStateChanged(e) {
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.peerFound) {
        id("messageDiv").innerHTML +=
            "Peer found. You may now pull your devices out of proximity.<br />";
    }
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.completed) {
        id("messageDiv").innerHTML += "Connected. You may now send a message.<br />";
        sendMessage(e.socket);
    }
}


// Click event for "Browse" button.
function findPeers() {
    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.browse) {

        Windows.Networking.Proximity.PeerFinder.findAllPeersAsync().done(
    function (peerInfoCollection) {
        if (peerInfoCollection.length > 0) {
            // Connect to first peer found - example only.
            // In your app, provide the user with a list of available peers.
            connectToPeer(peerInfoCollection[0]);
        }
    },
    function (err) {
        id("messageDiv").innerHTML += "Error finding peers: " + err + "<br />";
    });
    } else {
        id("messageDiv").innerHTML +=
  "Peer discovery using Wi-Fi Direct is not supported.<br />";
    }
}

function connectToPeer(peerInfo) {
    id("messageDiv").innerHTML += ("Peer found. Connecting to " + peerInfo.displayName + "<br />");
    Windows.Networking.Proximity.PeerFinder.connectAsync(peerInfo).done(
        function (socket) {
            id("messageDiv").innerHTML += "Connection successful. You may now send messages.<br />";
            sendMessage(socket);
        },
        function (err) {
            id("messageDiv").innerHTML += "Connection failed: " + err + "<br />";
        });

    requestingPeer = null;
}

function stopFindingPeers() {
    Windows.Networking.Proximity.PeerFinder.stop();
    started = false;
    if (proximitySocket != null) { closeSocket(); }
}

// Handle external connection requests.
var requestingPeer;

function connectionRequested(e) {
    id("messageDiv").innerHTML +=
        "Connection requested by " + e.peerInformation.DisplayName + ". " +
        "Click 'Accept Connection' to connect.";
    requestingPeer = e.PeerInformation;
}

function acceptConnection() {
    if (requestingPeer == null) {
        id("messageDiv").innerHTML += "No peer connection has been requested.";
        return;
    }

    connectToPeer(requestingPeer);
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName;
    Windows.Networking.Proximity.PeerFinder.ConnectionRequested += ConnectionRequested;

    // If activated from launch or from the background, create a peer connection.
    var args = e.Parameter as Windows.ApplicationModel.Activation.LaunchActivatedEventArgs;
    if (args != null && args.Kind == Windows.ApplicationModel.Activation.ActivationKind.Launch)
    {
        if (args.Arguments == "Windows.Networking.Proximity.PeerFinder:StreamSocket")
        {
            AdvertiseForPeersButton_Click(null, null);
        }
    }
}

protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
    if (_started)
    {
        // Detach the callback handler (there can only be one PeerConnectProgress handler).
        Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged -= TriggeredConnectionStateChanged;
        // Detach the incoming connection request event handler.
        Windows.Networking.Proximity.PeerFinder.ConnectionRequested -= ConnectionRequested;
        Windows.Networking.Proximity.PeerFinder.Stop();
        CloseSocket();
        _started = false;
    }
}

// Write a message to MessageBlock on the UI thread.
private Windows.UI.Core.CoreDispatcher messageDispatcher = Window.Current.CoreWindow.Dispatcher;

async private void WriteMessageText(string message, bool overwrite = false)
{
    await messageDispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        () =>
        {
            if (overwrite)
                MessageBlock.Text = message;
            else
                MessageBlock.Text += message;
        });
}

bool _started = false;

// Click event handler for "Advertise" button.
private void AdvertiseForPeersButton_Click(object sender, RoutedEventArgs e)
{
    if (_started) 
    {
        WriteMessageText("You are already advertising for a connection.
"); return; } Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text; if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) == Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) { Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged += TriggeredConnectionStateChanged; WriteMessageText("You can tap to connect a peer device that is " + "also advertising for a connection.
"); } else { WriteMessageText("Tap to connect is not supported.
"); } if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); } Windows.Networking.Proximity.PeerFinder.Start(); _started = true; } private void TriggeredConnectionStateChanged( object sender, Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs e) { if (e.State == Windows.Networking.Proximity.TriggeredConnectState.PeerFound) { WriteMessageText("Peer found. You may now pull your devices out of proximity.
"); } if (e.State == Windows.Networking.Proximity.TriggeredConnectState.Completed) { WriteMessageText("Connected. You may now send a message.
"); SendMessage(e.Socket); } } // Click event handler for "Browse" button. async private void FindPeersButton_Click(object sender, RoutedEventArgs e) { if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); return; } try { var peerInfoCollection = await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync(); if (peerInfoCollection.Count > 0) { // Connect to first peer found - example only. // In your app, provide the user with a list of available peers. ConnectToPeer(peerInfoCollection[0]); } } catch (Exception err) { WriteMessageText("Error finding peers: " + err.Message + "
"); } } async private void ConnectToPeer(Windows.Networking.Proximity.PeerInformation peerInfo) { WriteMessageText("Peer found. Connecting to " + peerInfo.DisplayName + "
"); try { Windows.Networking.Sockets.StreamSocket socket = await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo); WriteMessageText("Connection successful. You may now send messages.
"); SendMessage(socket); } catch (Exception err) { WriteMessageText("Connection failed: " + err.Message + "
"); } requestingPeer = null; } // Click event handler for "Stop" button. private void StopFindingPeersButton_Click(object sender, RoutedEventArgs e) { _started = false; Windows.Networking.Proximity.PeerFinder.Stop(); if (proximitySocket != null) { CloseSocket(); } } // Handle external connection requests. Windows.Networking.Proximity.PeerInformation requestingPeer; private void ConnectionRequested(object sender, Windows.Networking.Proximity.ConnectionRequestedEventArgs e) { requestingPeer = e.PeerInformation; WriteMessageText("Connection requested by " + requestingPeer.DisplayName + ". " + "Click 'Accept Connection' to connect."); } private void AcceptConnectionButton_Click(object sender, RoutedEventArgs e) { if (requestingPeer == null) { WriteMessageText("No peer connection has been requested."); return; } ConnectToPeer(requestingPeer); }
Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName
    AddHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested

    ' If activated from launch or from the background, create a peer connection.
    Dim args = TryCast(e.Parameter, Windows.ApplicationModel.Activation.LaunchActivatedEventArgs)
    If args IsNot Nothing AndAlso args.Kind = Windows.ApplicationModel.Activation.ActivationKind.Launch Then

        If args.Arguments = "Windows.Networking.Proximity.PeerFinder:StreamSocket" Then
            AdvertiseForPeersButton_Click()
        End If
    End If
End Sub

Protected Overrides Sub OnNavigatingFrom(e As Navigation.NavigatingCancelEventArgs)
    If _started Then
        ' Detach the callback handler (there can only be one PeerConnectProgress handler).
        RemoveHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged, AddressOf TriggeredConnectionStateChanged
        ' Detach the incoming connection request event handler.
        RemoveHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested
        Windows.Networking.Proximity.PeerFinder.Stop()
        CloseSocket()
        _started = False
    End If
End Sub

' Write a message to MessageBlock on the UI thread.
Private Async Sub WriteMessageText(message As String, Optional overwrite As Boolean = False)
    Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        Sub()
            If overwrite Then
                MessageBlock.Text = message
            Else
                MessageBlock.Text &= message
            End If
        End Sub)
End Sub

Private _started As Boolean = False

' Click event handler for "Advertise" button.
Private Sub AdvertiseForPeersButton_Click()

    If _started Then
        WriteMessageText("You are already advertising for a connection." & vbCrLf)
        Return
    End If

    Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text

    If ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) =
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) Then

        AddHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged,
            AddressOf TriggeredConnectionStateChanged

        WriteMessageText("You can tap to connect a peer device that is " &
                         "also advertising for a connection." & vbCrLf)
    Else
        WriteMessageText("Tap to connect is not supported." & vbCrLf)
    End If

    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
    End If

    Windows.Networking.Proximity.PeerFinder.Start()
    _started = True
End Sub

Private Sub TriggeredConnectionStateChanged(
    sender As Object,
    e As Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs)

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.PeerFound Then

        WriteMessageText("Peer found. You may now pull your devices out of proximity." & vbCrLf)
    End If

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.Completed Then
        WriteMessageText("Connected. You may now send a message." & vbCrLf)
        SendMessage(e.Socket)
    End If
End Sub

' Click event handler for "Browse" button.
Private Async Sub FindPeersButton_Click()
    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
        Return
    End If

    Try
        Dim peerInfoCollection = Await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync()
        If peerInfoCollection.Count > 0 Then
            ' Connect to first peer found - example only.
            ' In your app, provide the user with a list of available peers.
            ConnectToPeer(peerInfoCollection(0))
        End If
    Catch err As Exception
        WriteMessageText("Error finding peers: " & err.Message & vbCrLf)
    End Try
End Sub

Private Async Sub ConnectToPeer(peerInfo As Windows.Networking.Proximity.PeerInformation)

    WriteMessageText("Peer found. Connecting to " & peerInfo.DisplayName & vbCrLf)
    Try
        Dim socket = Await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo)

        WriteMessageText("Connection successful. You may now send messages." & vbCrLf)
        SendMessage(socket)
    Catch err As Exception
        WriteMessageText("Connection failed: " & err.Message & vbCrLf)
    End Try

    requestingPeer = Nothing
End Sub

' Click event handler for "Stop" button.
Private Sub StopFindingPeersButton_Click()

    _started = False
    Windows.Networking.Proximity.PeerFinder.Stop()
    If proximitySocket IsNot Nothing Then CloseSocket()
End Sub

' Handle external connection requests.
Private requestingPeer As Windows.Networking.Proximity.PeerInformation

Private Sub ConnectionRequested(sender As Object,
    e As Windows.Networking.Proximity.ConnectionRequestedEventArgs)

    requestingPeer = e.PeerInformation

    WriteMessageText("Connection requested by " & requestingPeer.DisplayName & ". " &
        "Click 'Accept Connection' to connect.")
End Sub

Private Sub AcceptConnectionButton_Click()
    If requestingPeer Is Nothing Then
        WriteMessageText("No peer connection has been requested.")
        Return
    End If

    ConnectToPeer(requestingPeer)
End Sub

Remarks

The ConnectionRequested event occurs when a remote peer calls the FindAllPeersAsync method, finds the current peer, and passes that peer information to the ConnectAsync method to request a connection.

Important

The Proximity APIs do not provide authentication. You should avoid exchanging sensitive data with these APIs.

See Also

TriggeredConnectionStateChanged TriggeredConnectionStateChanged TriggeredConnectionStateChanged TriggeredConnectionStateChanged

Occurs during a tap gesture from a remote peer.

public : event TypedEventHandler TriggeredConnectionStateChanged<Platform::Object,  TriggeredConnectionStateChangedEventArgs>
public event TypedEventHandler TriggeredConnectionStateChanged<object,  TriggeredConnectionStateChangedEventArgs>
Public Event TypedEventHandler TriggeredConnectionStateChanged( Of ( Of object ), ( Of  TriggeredConnectionStateChangedEventArgs ))
function onTriggeredConnectionStateChanged(eventArgs){/* Your code */}


peerFinder.addEventListener("triggeredConnectionStateChanged", onTriggeredConnectionStateChanged);
peerFinder.removeEventListener("triggeredConnectionStateChanged", onTriggeredConnectionStateChanged);
Additional features and requirements
Device family
Windows 10 (introduced v10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)
Capabilities
ID_CAP_NETWORKING [Windows Phone] ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Examples

var started = false;

// Click event for "Advertise" button.
function advertiseForPeers(launchedFromTap) {
    Windows.Networking.Proximity.PeerFinder.displayName = displayNameTextBox.Text;

    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.triggered) {

        Windows.Networking.Proximity.PeerFinder.addEventListener(
            "triggeredconnectionstatechanged", triggeredConnectionStateChanged);

        id("messageDiv").innerHTML +=
            "You can tap to connect a peer device that is " +
            "also advertising for a connection.<br />";
    } else {
        id("messageDiv").innerHTML +=
      "Tap to connect is not supported.<br />";
    }

    if (!launchedFromTap) {
        if (!(Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
              Windows.Networking.Proximity.PeerDiscoveryTypes.Browse)) {
            id("messageDiv").innerHTML +=
                "Peer discovery using Wi-Fi Direct is not supported.<br />";
        }
    }

    if (!started) {
        Windows.Networking.Proximity.PeerFinder.start();
        started = true;
    }
}

function triggeredConnectionStateChanged(e) {
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.peerFound) {
        id("messageDiv").innerHTML +=
            "Peer found. You may now pull your devices out of proximity.<br />";
    }
    if (e.state === Windows.Networking.Proximity.TriggeredConnectState.completed) {
        id("messageDiv").innerHTML += "Connected. You may now send a message.<br />";
        sendMessage(e.socket);
    }
}


// Click event for "Browse" button.
function findPeers() {
    if (Windows.Networking.Proximity.PeerFinder.supportedDiscoveryTypes &
        Windows.Networking.Proximity.PeerDiscoveryTypes.browse) {

        Windows.Networking.Proximity.PeerFinder.findAllPeersAsync().done(
    function (peerInfoCollection) {
        if (peerInfoCollection.length > 0) {
            // Connect to first peer found - example only.
            // In your app, provide the user with a list of available peers.
            connectToPeer(peerInfoCollection[0]);
        }
    },
    function (err) {
        id("messageDiv").innerHTML += "Error finding peers: " + err + "<br />";
    });
    } else {
        id("messageDiv").innerHTML +=
  "Peer discovery using Wi-Fi Direct is not supported.<br />";
    }
}

function connectToPeer(peerInfo) {
    id("messageDiv").innerHTML += ("Peer found. Connecting to " + peerInfo.displayName + "<br />");
    Windows.Networking.Proximity.PeerFinder.connectAsync(peerInfo).done(
        function (socket) {
            id("messageDiv").innerHTML += "Connection successful. You may now send messages.<br />";
            sendMessage(socket);
        },
        function (err) {
            id("messageDiv").innerHTML += "Connection failed: " + err + "<br />";
        });

    requestingPeer = null;
}

function stopFindingPeers() {
    Windows.Networking.Proximity.PeerFinder.stop();
    started = false;
    if (proximitySocket != null) { closeSocket(); }
}

// Handle external connection requests.
var requestingPeer;

function connectionRequested(e) {
    id("messageDiv").innerHTML +=
        "Connection requested by " + e.peerInformation.DisplayName + ". " +
        "Click 'Accept Connection' to connect.";
    requestingPeer = e.PeerInformation;
}

function acceptConnection() {
    if (requestingPeer == null) {
        id("messageDiv").innerHTML += "No peer connection has been requested.";
        return;
    }

    connectToPeer(requestingPeer);
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName;
    Windows.Networking.Proximity.PeerFinder.ConnectionRequested += ConnectionRequested;

    // If activated from launch or from the background, create a peer connection.
    var args = e.Parameter as Windows.ApplicationModel.Activation.LaunchActivatedEventArgs;
    if (args != null && args.Kind == Windows.ApplicationModel.Activation.ActivationKind.Launch)
    {
        if (args.Arguments == "Windows.Networking.Proximity.PeerFinder:StreamSocket")
        {
            AdvertiseForPeersButton_Click(null, null);
        }
    }
}

protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
{
    if (_started)
    {
        // Detach the callback handler (there can only be one PeerConnectProgress handler).
        Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged -= TriggeredConnectionStateChanged;
        // Detach the incoming connection request event handler.
        Windows.Networking.Proximity.PeerFinder.ConnectionRequested -= ConnectionRequested;
        Windows.Networking.Proximity.PeerFinder.Stop();
        CloseSocket();
        _started = false;
    }
}

// Write a message to MessageBlock on the UI thread.
private Windows.UI.Core.CoreDispatcher messageDispatcher = Window.Current.CoreWindow.Dispatcher;

async private void WriteMessageText(string message, bool overwrite = false)
{
    await messageDispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        () =>
        {
            if (overwrite)
                MessageBlock.Text = message;
            else
                MessageBlock.Text += message;
        });
}

bool _started = false;

// Click event handler for "Advertise" button.
private void AdvertiseForPeersButton_Click(object sender, RoutedEventArgs e)
{
    if (_started) 
    {
        WriteMessageText("You are already advertising for a connection.
"); return; } Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text; if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) == Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) { Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged += TriggeredConnectionStateChanged; WriteMessageText("You can tap to connect a peer device that is " + "also advertising for a connection.
"); } else { WriteMessageText("Tap to connect is not supported.
"); } if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); } Windows.Networking.Proximity.PeerFinder.Start(); _started = true; } private void TriggeredConnectionStateChanged( object sender, Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs e) { if (e.State == Windows.Networking.Proximity.TriggeredConnectState.PeerFound) { WriteMessageText("Peer found. You may now pull your devices out of proximity.
"); } if (e.State == Windows.Networking.Proximity.TriggeredConnectState.Completed) { WriteMessageText("Connected. You may now send a message.
"); SendMessage(e.Socket); } } // Click event handler for "Browse" button. async private void FindPeersButton_Click(object sender, RoutedEventArgs e) { if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes & Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) != Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) { WriteMessageText("Peer discovery using Wi-Fi Direct is not supported.
"); return; } try { var peerInfoCollection = await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync(); if (peerInfoCollection.Count > 0) { // Connect to first peer found - example only. // In your app, provide the user with a list of available peers. ConnectToPeer(peerInfoCollection[0]); } } catch (Exception err) { WriteMessageText("Error finding peers: " + err.Message + "
"); } } async private void ConnectToPeer(Windows.Networking.Proximity.PeerInformation peerInfo) { WriteMessageText("Peer found. Connecting to " + peerInfo.DisplayName + "
"); try { Windows.Networking.Sockets.StreamSocket socket = await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo); WriteMessageText("Connection successful. You may now send messages.
"); SendMessage(socket); } catch (Exception err) { WriteMessageText("Connection failed: " + err.Message + "
"); } requestingPeer = null; } // Click event handler for "Stop" button. private void StopFindingPeersButton_Click(object sender, RoutedEventArgs e) { _started = false; Windows.Networking.Proximity.PeerFinder.Stop(); if (proximitySocket != null) { CloseSocket(); } } // Handle external connection requests. Windows.Networking.Proximity.PeerInformation requestingPeer; private void ConnectionRequested(object sender, Windows.Networking.Proximity.ConnectionRequestedEventArgs e) { requestingPeer = e.PeerInformation; WriteMessageText("Connection requested by " + requestingPeer.DisplayName + ". " + "Click 'Accept Connection' to connect."); } private void AcceptConnectionButton_Click(object sender, RoutedEventArgs e) { if (requestingPeer == null) { WriteMessageText("No peer connection has been requested."); return; } ConnectToPeer(requestingPeer); }
Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)
    DisplayNameTextBox.Text = Windows.Networking.Proximity.PeerFinder.DisplayName
    AddHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested

    ' If activated from launch or from the background, create a peer connection.
    Dim args = TryCast(e.Parameter, Windows.ApplicationModel.Activation.LaunchActivatedEventArgs)
    If args IsNot Nothing AndAlso args.Kind = Windows.ApplicationModel.Activation.ActivationKind.Launch Then

        If args.Arguments = "Windows.Networking.Proximity.PeerFinder:StreamSocket" Then
            AdvertiseForPeersButton_Click()
        End If
    End If
End Sub

Protected Overrides Sub OnNavigatingFrom(e As Navigation.NavigatingCancelEventArgs)
    If _started Then
        ' Detach the callback handler (there can only be one PeerConnectProgress handler).
        RemoveHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged, AddressOf TriggeredConnectionStateChanged
        ' Detach the incoming connection request event handler.
        RemoveHandler Windows.Networking.Proximity.PeerFinder.ConnectionRequested, AddressOf ConnectionRequested
        Windows.Networking.Proximity.PeerFinder.Stop()
        CloseSocket()
        _started = False
    End If
End Sub

' Write a message to MessageBlock on the UI thread.
Private Async Sub WriteMessageText(message As String, Optional overwrite As Boolean = False)
    Await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
        Sub()
            If overwrite Then
                MessageBlock.Text = message
            Else
                MessageBlock.Text &= message
            End If
        End Sub)
End Sub

Private _started As Boolean = False

' Click event handler for "Advertise" button.
Private Sub AdvertiseForPeersButton_Click()

    If _started Then
        WriteMessageText("You are already advertising for a connection." & vbCrLf)
        Return
    End If

    Windows.Networking.Proximity.PeerFinder.DisplayName = DisplayNameTextBox.Text

    If ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) =
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) Then

        AddHandler Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged,
            AddressOf TriggeredConnectionStateChanged

        WriteMessageText("You can tap to connect a peer device that is " &
                         "also advertising for a connection." & vbCrLf)
    Else
        WriteMessageText("Tap to connect is not supported." & vbCrLf)
    End If

    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
    End If

    Windows.Networking.Proximity.PeerFinder.Start()
    _started = True
End Sub

Private Sub TriggeredConnectionStateChanged(
    sender As Object,
    e As Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs)

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.PeerFound Then

        WriteMessageText("Peer found. You may now pull your devices out of proximity." & vbCrLf)
    End If

    If e.State = Windows.Networking.Proximity.TriggeredConnectState.Completed Then
        WriteMessageText("Connected. You may now send a message." & vbCrLf)
        SendMessage(e.Socket)
    End If
End Sub

' Click event handler for "Browse" button.
Private Async Sub FindPeersButton_Click()
    If (Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes And
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse) <>
        Windows.Networking.Proximity.PeerDiscoveryTypes.Browse Then

        WriteMessageText("Peer discovery using Wifi-Direct is not supported." & vbCrLf)
        Return
    End If

    Try
        Dim peerInfoCollection = Await Windows.Networking.Proximity.PeerFinder.FindAllPeersAsync()
        If peerInfoCollection.Count > 0 Then
            ' Connect to first peer found - example only.
            ' In your app, provide the user with a list of available peers.
            ConnectToPeer(peerInfoCollection(0))
        End If
    Catch err As Exception
        WriteMessageText("Error finding peers: " & err.Message & vbCrLf)
    End Try
End Sub

Private Async Sub ConnectToPeer(peerInfo As Windows.Networking.Proximity.PeerInformation)

    WriteMessageText("Peer found. Connecting to " & peerInfo.DisplayName & vbCrLf)
    Try
        Dim socket = Await Windows.Networking.Proximity.PeerFinder.ConnectAsync(peerInfo)

        WriteMessageText("Connection successful. You may now send messages." & vbCrLf)
        SendMessage(socket)
    Catch err As Exception
        WriteMessageText("Connection failed: " & err.Message & vbCrLf)
    End Try

    requestingPeer = Nothing
End Sub

' Click event handler for "Stop" button.
Private Sub StopFindingPeersButton_Click()

    _started = False
    Windows.Networking.Proximity.PeerFinder.Stop()
    If proximitySocket IsNot Nothing Then CloseSocket()
End Sub

' Handle external connection requests.
Private requestingPeer As Windows.Networking.Proximity.PeerInformation

Private Sub ConnectionRequested(sender As Object,
    e As Windows.Networking.Proximity.ConnectionRequestedEventArgs)

    requestingPeer = e.PeerInformation

    WriteMessageText("Connection requested by " & requestingPeer.DisplayName & ". " &
        "Click 'Accept Connection' to connect.")
End Sub

Private Sub AcceptConnectionButton_Click()
    If requestingPeer Is Nothing Then
        WriteMessageText("No peer connection has been requested.")
        Return
    End If

    ConnectToPeer(requestingPeer)
End Sub

Remarks

You can determine when a peer is available to connect to, and the progress of a connection to a peer, by using the TriggeredConnectionStateChanged event. Use the TriggeredConnectionStateChanged event to determine when a new peer has been found and to access the connection to that peer after you've finished connecting.

The TriggeredConnectionStateChanged event occurs several times during a tap gesture. You can determine where you are in the connection process by using the State property.

The first State value in a Proximity connection is PeerFound. At this point, you can tell users of your app that the Proximity gesture is complete and they can pull their devices away.

If the State property returns Connecting, you know that your device initiated the tap gesture. If the State property returns Listening, you know that the other device initiated the tap gesture. This information is useful in determining which peer should initiate communications when the connection is complete.

When the State property returns Completed, you can access the Socket property to obtain a reference to a StreamSocket object. You can use this reference to communicate with the peer app. The transport over which this communication takes place on this socket connection will either be Bluetooth, Infrastructure or Wi-Fi Direct.

Wi-Fi Direct is not supported for Windows Phone 8.x apps.

See Also

See Also