PeerFinder.FindAllPeersAsync Método

Definición

Espacio de nombres:

Windows.Networking.Proximity

Examina de forma asincrónica los dispositivos del mismo nivel que ejecutan la misma aplicación dentro del intervalo inalámbrico.

public:
 static IAsyncOperation<IVectorView<PeerInformation ^> ^> ^ FindAllPeersAsync();

/// [Windows.Foundation.Metadata.RemoteAsync]
 static IAsyncOperation<IVectorView<PeerInformation>> FindAllPeersAsync();

[Windows.Foundation.Metadata.RemoteAsync]
public static IAsyncOperation<IReadOnlyList<PeerInformation>> FindAllPeersAsync();

function findAllPeersAsync()

Public Shared Function FindAllPeersAsync () As IAsyncOperation(Of IReadOnlyList(Of PeerInformation))

Devoluciones

IAsyncOperation<IVectorView<PeerInformation>>

IAsyncOperation<IReadOnlyList<PeerInformation>>

La operación asincrónica para explorar los dispositivos del mismo nivel que ejecutan la aplicación.

Atributos

RemoteAsyncAttribute

Requisitos de Windows

Características de aplicaciones

ID_CAP_NETWORKING [Windows Phone] ID_CAP_NETWORKING [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Ejemplos

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

Comentarios

Si la aplicación se ejecuta en un equipo, puede buscar equipos del mismo nivel que ejecuten la aplicación. En este caso, la detección del mismo nivel se realiza en Wi-Fi Direct. Si la aplicación se ejecuta en un teléfono, puede buscar teléfonos del mismo nivel que ejecutan la aplicación. En este caso, la detección del mismo nivel se realiza a través de Bluetooth. Dado que el transporte usado para la detección del mismo nivel difiere entre pc y teléfono, la aplicación que se ejecuta en un equipo solo puede encontrar equipos del mismo nivel y la aplicación que se ejecuta en un teléfono solo puede encontrar teléfonos del mismo nivel.

Cuando la operación de exploración asincrónica finaliza correctamente, devuelve una lista de elementos del mismo nivel que están dentro del intervalo inalámbrico. Un elemento del mismo nivel es un dispositivo que tiene una aplicación que se ejecuta en primer plano con un identificador de aplicación coincidente. Un elemento del mismo nivel también puede tener un identificador de examen coincidente especificado como una identidad alternativa. Para obtener más información, vea AlternateIdentities.

Si una aplicación llama al método ConnectAsync para crear una conexión con un mismo nivel, la aplicación ya no anunciará una conexión y no la encontrará el método FindAllPeersAsync hasta que la aplicación llame al método Close para cerrar la conexión de socket.

Solo encontrará elementos del mismo nivel en los que el dispositivo está dentro del intervalo inalámbrico y la aplicación del mismo nivel se ejecuta en primer plano. Si una aplicación del mismo nivel se ejecuta en segundo plano, la proximidad no anuncia las conexiones del mismo nivel.

Como alternativa al método FindAllPeersAsync, puede buscar dinámicamente aplicaciones del mismo nivel a medida que se detectan dentro del intervalo mediante el objeto PeerWatcher .

Windows Phone 8

Wi-Fi Direct no se admite en Windows Phone 8.

Consulte también

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