ProximityDevice.SubscribeForMessage(String, MessageReceivedHandler) Methode

Referenz

Definition

Namespace:: Windows.Networking.Proximity

Wichtig

Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.

Bearbeiten

Erstellt ein Abonnement für einen angegebenen Nachrichtentyp.

public:
 virtual long long SubscribeForMessage(Platform::String ^ messageType, MessageReceivedHandler ^ messageReceivedHandler) = SubscribeForMessage;

long SubscribeForMessage(winrt::hstring const& messageType, MessageReceivedHandler const& messageReceivedHandler);

public long SubscribeForMessage(string messageType, MessageReceivedHandler messageReceivedHandler);

function subscribeForMessage(messageType, messageReceivedHandler)

Public Function SubscribeForMessage (messageType As String, messageReceivedHandler As MessageReceivedHandler) As Long

Parameter

messageType: String
Platform::String

winrt::hstring

Der Typ der Nachricht, die an dieses Abonnement übermittelt werden soll.

messageReceivedHandler: MessageReceivedHandler

Der Handler, den der Näherungsanbieter aufruft, wenn er eine Nachricht übermittelt.

Gibt zurück

Int64

long long

long

Eine eindeutige ID für das Abonnement.

Windows-Anforderungen

App-Funktionen

ID_CAP_PROXIMITY [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Beispiele

Windows.Networking.Proximity.ProximityDevice proximityDevice;
long publishedMessageId = -1;
long subscribedMessageId = -1;

private void initializeProximityDevice()
{
    proximityDevice = Windows.Networking.Proximity.ProximityDevice.GetDefault();

    if (proximityDevice != null)
    {
        PublishMessageButton.Click += PublishMessage;
        SubscribeForMessageButton.Click += SubscribeForMessage;
        StopSubscribingForMessageButton.Click += StopSubscribingForMessage;
        StopPublishingMessageButton.Click += StopPublishingMessage;
    }
    else
    {
        WriteMessageText("Failed to initialized proximity device.\n");
    }
}

private void PublishMessage(object sender, RoutedEventArgs e)
{
    // Stop publishing the current message.
    if (publishedMessageId != -1)
    {
        proximityDevice.StopPublishingMessage(publishedMessageId);
    }

    publishedMessageId = 
        proximityDevice.PublishMessage("Windows.SampleMessage", MessageTextBlock.Text);
}

private void SubscribeForMessage(object sender, RoutedEventArgs e)
{
    // Only subscribe for the message one time.
    if (subscribedMessageId == -1)
    {
        subscribedMessageId = 
        proximityDevice.SubscribeForMessage("Windows.SampleMessage", messageReceived);
    }
}

private void messageReceived(
    Windows.Networking.Proximity.ProximityDevice device, 
    Windows.Networking.Proximity.ProximityMessage message)
{
    MessageBlock.Text += "Message received: " + message.DataAsString + "\n";
}

private void StopSubscribingForMessage(object sender, RoutedEventArgs e)
{
    proximityDevice.StopSubscribingForMessage(subscribedMessageId);
    subscribedMessageId = -1;
}

private void StopPublishingMessage(object sender, RoutedEventArgs e)
{
    proximityDevice.StopPublishingMessage(publishedMessageId);
    publishedMessageId = -1;
}

// 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;
        });
}

Private proximityDevice As Windows.Networking.Proximity.ProximityDevice
Private publishedMessageId As Long = -1
Private subscribedMessageId As Long = -1

Private Sub initializeProximityDevice()
    proximityDevice = Windows.Networking.Proximity.ProximityDevice.GetDefault()

    If proximityDevice IsNot Nothing Then
        AddHandler PublishMessageButton.Click, AddressOf PublishMessage
        AddHandler SubscribeForMessageButton.Click, AddressOf SubscribeForMessage
        AddHandler StopSubscribingForMessageButton.Click, AddressOf StopSubscribingForMessage
        AddHandler StopPublishingMessageButton.Click, AddressOf StopPublishingMessage
    Else
        WriteMessageText("Failed to initialized proximity device." & vbTab)
    End If
End Sub

Private Sub PublishMessage(sender As Object, e As RoutedEventArgs)
    ' Stop publishing the current message.
    If publishedMessageId <> -1 Then
        proximityDevice.StopPublishingMessage(publishedMessageId)
    End If

    publishedMessageId =
        proximityDevice.PublishMessage("Windows.SampleMessage", MessageTextBlock.Text)
End Sub

Private Sub SubscribeForMessage(sender As Object, e As RoutedEventArgs)
    ' Only subscribe for the message one time.
    If subscribedMessageId = -1 Then
        subscribedMessageId =
        proximityDevice.SubscribeForMessage("Windows.SampleMessage", AddressOf messageReceived)
    End If
End Sub

Private Sub messageReceived(
    device As Windows.Networking.Proximity.ProximityDevice,
    message As Windows.Networking.Proximity.ProximityMessage)

    MessageBlock.Text &= "Message received: " & message.DataAsString & vbTab
End Sub

Private Sub StopSubscribingForMessage(sender As Object, e As RoutedEventArgs)
    proximityDevice.StopSubscribingForMessage(subscribedMessageId)
    subscribedMessageId = -1
End Sub

Private Sub StopPublishingMessage(sender As Object, e As RoutedEventArgs)
    proximityDevice.StopPublishingMessage(publishedMessageId)
    publishedMessageId = -1
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

Hinweise

Nachdem Ihre App die SubscribeForMessage-Methode aufgerufen hat, empfängt sie Nachrichten, die mit demselben Nachrichtentyp (wie durch den messageType-Parameter angegeben) von allen benachbarten Geräten veröffentlicht werden. Ausführliche Informationen zu den verschiedenen Nachrichtentypen finden Sie in den Hinweisen im Referenzthema PublishBinaryMessage(String, IBuffer).

Sie können ein Abonnement kündigen, indem Sie die von der SubscribeForMessage-Methode zurückgegebene Abonnement-ID an die StopSubscribingForMessage-Methode übergeben.

Sie können eine Nachricht für einen Abonnenten veröffentlichen, indem Sie die Methode PublishMessage, PublishBinaryMessage oder PublishUriMessage verwenden.

Wichtig

Die Näherungs-APIs bieten keine Authentifizierung, Verschlüsselung oder Nachrichtenintegrität. Verwenden Sie die Nähe nicht, um vertrauliche Benutzerinformationen wie Kennwörter, Finanzdaten, SMS, E-Mails, Fotos oder Behörden-ID-Nummern auszutauschen.

Gilt für:

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