TriggeredConnectionStateChangedEventArgs.State Property

Definition

Namespace:

Windows.Networking.Proximity

Gets the state of the connection in progress.

public:
 property TriggeredConnectState State { TriggeredConnectState get(); };

TriggeredConnectState State();

public TriggeredConnectState State { get; }

var triggeredConnectState = triggeredConnectionStateChangedEventArgs.state;

Public ReadOnly Property State As TriggeredConnectState

Property Value

TriggeredConnectState

The state of the connection in progress.

Windows requirements

App capabilities

ID_CAP_PROXIMITY [Windows Phone] proximity ID_CAP_PROXIMITY [Windows Phone]

Examples

// Click event for "Start" button.

private void StartFindingPeersButton_Click(object sender, RoutedEventArgs e)
{
    if ((Windows.Networking.Proximity.PeerFinder.SupportedDiscoveryTypes &
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered) ==
         Windows.Networking.Proximity.PeerDiscoveryTypes.Triggered)
    {
        Windows.Networking.Proximity.PeerFinder.Start();

        Windows.Networking.Proximity.PeerFinder.TriggeredConnectionStateChanged += 
            TriggeredConnectionStateChanged;

        WriteMessageText("Waiting for peers. Enter proximity to connect. " +
            "Call PeerFinder.start() on the peer to send and receive messages.\n");
    }
    else {
        WriteMessageText("Peer discovery using tapping is not supported.\n");
    }
}

private void TriggeredConnectionStateChanged(object sender,
    Windows.Networking.Proximity.TriggeredConnectionStateChangedEventArgs e)
{
    if (e.State == Windows.Networking.Proximity.TriggeredConnectState.Completed)
    {
        WriteMessageText("Connected. You may now send a message.\n");
        SendMessage(e.Socket);
    }
}

Windows.Networking.Sockets.StreamSocket proximitySocket;
Windows.Storage.Streams.DataWriter dataWriter;

// Reference socket streams for writing and reading messages.
private void SendMessage(Windows.Networking.Sockets.StreamSocket socket) {
    // Get the network socket from the proximity connection.
    proximitySocket = socket;

    // Create DataWriter for writing messages to peers.
    dataWriter = new Windows.Storage.Streams.DataWriter(proximitySocket.OutputStream);

    // Listen for messages from peers.
    Windows.Storage.Streams.DataReader dataReader = 
            new Windows.Storage.Streams.DataReader(proximitySocket.InputStream);
    StartReader(proximitySocket, dataReader);
}

// Send a message to the socket.
private async void SendMessageText() {
    string msg = SendMessageTextBlock.Text;

    if (msg.Length > 0) {
        var msgLength = dataWriter.MeasureString(msg);
        dataWriter.WriteInt32(msg.Length);
        dataWriter.WriteString(msg);
        try
        {
            await dataWriter.StoreAsync();
            WriteMessageText("Message sent: " + msg  + "\n");
        }
        catch (Exception e)
        {
            WriteMessageText("Send error: " + e.Message + "\n");
        }
    }
}

// Read out and print the message received from the socket.
private async void StartReader(
    Windows.Networking.Sockets.StreamSocket socket, 
    Windows.Storage.Streams.DataReader reader)
{
    uint initialLength = 4;

    try
    {
        await reader.LoadAsync(initialLength);
        uint msgLength = (uint)reader.ReadInt32();

        try
        {
            await reader.LoadAsync(msgLength);
            string message = reader.ReadString(msgLength);
            WriteMessageText("Received message: " + message + "\n");

            // After receiving a message, listen for the next message.
            StartReader(socket, reader);
        }
        catch (Exception e)
        {
            WriteMessageText("Error: " + e.Message + "\n");
            socket.Dispose();
        }
    }
    catch (Exception e)
    {
        WriteMessageText("Error: " + e.Message + "\n");
        socket.Dispose();
    }
}

// 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;
        });
}

' Click event for "Start" button.

Private Sub StartFindingPeersButton_Click(sender As Object, e As RoutedEventArgs)

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

        Windows.Networking.Proximity.PeerFinder.Start()

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

        WriteMessageText("Waiting for peers. Enter proximity to connect. " &
            "Call PeerFinder.start() on the peer to send and receive messages." & vbTab)
    Else
        WriteMessageText("Peer discovery using tapping is not supported." & vbTab)
    End If
End Sub

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

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

Private proximitySocket As Windows.Networking.Sockets.StreamSocket
Private dataWriter As Windows.Storage.Streams.DataWriter

' Reference socket streams for writing and reading messages.
Private Sub SendMessage(socket As Windows.Networking.Sockets.StreamSocket)
    ' Get the network socket from the proximity connection.
    proximitySocket = socket

    ' Create DataWriter for writing messages to peers.
    dataWriter = New Windows.Storage.Streams.DataWriter(proximitySocket.OutputStream)

    ' Listen for messages from peers.
    Dim dataReader = New Windows.Storage.Streams.DataReader(proximitySocket.InputStream)
    StartReader(proximitySocket, dataReader)
End Sub

' Send a message to the socket.
Private Async Sub SendMessageText()
    Dim msg = SendMessageTextBlock.Text

    If msg.Length > 0 Then
        Dim msgLength = dataWriter.MeasureString(msg)
        dataWriter.WriteInt32(msg.Length)
        dataWriter.WriteString(msg)
        Try
            Await dataWriter.StoreAsync()
            WriteMessageText("Message sent: " & msg & vbTab)
        Catch e As Exception
            WriteMessageText("Send error: " & e.Message & vbTab)
        End Try
    End If
End Sub

' Read out and print the message received from the socket.
Private Async Sub StartReader(
    socket As Windows.Networking.Sockets.StreamSocket,
    reader As Windows.Storage.Streams.DataReader)

    Dim initialLength As UInteger = 4

    Try
        Await reader.LoadAsync(initialLength)
        Dim msgLength = CType(reader.ReadInt32(), UInteger)

        Try
            Await reader.LoadAsync(msgLength)
            Dim message = reader.ReadString(msgLength)
            WriteMessageText("Received message: " & message & vbTab)

            ' After receiving a message, listen for the next message.
            StartReader(socket, reader)
        Catch e As Exception
            WriteMessageText("Error: " & e.Message & vbTab)
            socket.Dispose()
        End Try
    Catch e As Exception
        WriteMessageText("Error: " & e.Message & vbTab)
        socket.Dispose()
    End Try
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

See also

• TriggeredConnectionStateChanged
• Proximity and Tapping (C#/VB/C++)
• Proximity sample