PeerRole Enum

Definition

Describes the role of the peer app when connected to multiple peers.

public enum class PeerRole
/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
enum class PeerRole
[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
public enum PeerRole
var value = Windows.Networking.Proximity.PeerRole.peer
Public Enum PeerRole
Inheritance
PeerRole
Attributes

Windows requirements

Device family
Windows 10 (introduced in 10.0.10240.0 - for Xbox, see UWP features that aren't yet supported on Xbox)
API contract
Windows.Foundation.UniversalApiContract (introduced in v1.0)
App capabilities
proximity

Fields

Client 2

The app is a client peer app in a multi-peer connection.

Host 1

The app is the host peer app in a multi-peer connection.

Peer 0

The app is part of a two-peer connection.

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.\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");
        }

        // 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;
        });
}

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 four 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.

Applies to

See also