ProximityDevice.SubscribeForMessage(String, MessageReceivedHandler) Método

Definición

Espacio de nombres:

Windows.Networking.Proximity

Crea una suscripción para un tipo de mensaje especificado.

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

Parámetros

messageType

String

Platform::String

winrt::hstring

Tipo de mensaje que se va a entregar a esta suscripción.

messageReceivedHandler

MessageReceivedHandler

Controlador al que llamará el proveedor de proximidad cuando entregue un mensaje.

Devoluciones

Int64

long long

long

Un identificador único para la suscripción.

Requisitos de Windows

Características de aplicaciones

ID_CAP_PROXIMITY [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Ejemplos

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

Comentarios

Después de que la aplicación llame al método SubscribeForMessage, recibirá mensajes publicados con el mismo tipo de mensaje (como se indica en el parámetro messageType ) desde cualquier dispositivo proxy. Para obtener más información sobre los distintos tipos de mensajes, vea los comentarios del tema de referencia PublishBinaryMessage(String, IBuffer).

Puede cancelar una suscripción pasando el identificador de suscripción devuelto por el método SubscribeForMessage al método StopSubscribingForMessage .

Puede publicar un mensaje en un suscriptor mediante el método PublishMessage, PublishBinaryMessage o PublishUriMessage .

Importante

Las API de proximidad no proporcionan autenticación, cifrado ni integridad de mensajes. No use la proximidad para intercambiar información confidencial del usuario, como contraseñas, datos financieros, mensajes de texto, correo electrónico, fotografías o números de identificación gubernamentales.

Consulte también

• Proximidad y pulsación (C#/VB/C++)
• Muestra de proximidad