private async void Start_Click(object sender, RoutedEventArgs e)
{
// Have we connected yet?
if (streamWebSocket != null)
{
rootPage.NotifyUser("Already connected", NotifyType.StatusMessage);
return;
}
// Validating the URI is required since it was received from an untrusted source (user input).
// The URI is validated by calling TryGetUri() that will return 'false' for strings that are not
// valid WebSocket URIs.
// Note that when enabling the text box users may provide URIs to machines on the intrAnet
// or intErnet. In these cases the app requires the "Home or Work Networking" or
// "Internet (Client)" capability respectively.
Uri server;
if (!rootPage.TryGetUri(ServerAddressField.Text, out server))
{
return;
}
try
{
rootPage.NotifyUser("Connecting to: " + server, NotifyType.StatusMessage);
streamWebSocket = new StreamWebSocket();
// Dispatch close event on UI thread. This allows us to avoid synchronizing access to streamWebSocket.
streamWebSocket.Closed += async (senderSocket, args) =>
{
await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => Closed(senderSocket, args));
};
await streamWebSocket.ConnectAsync(server);
readBuffer = new byte[1000];
// Start a background task to continuously read for incoming data
Task receiving = Task.Factory.StartNew(Scenario2ReceiveData,
streamWebSocket.InputStream.AsStreamForRead(), TaskCreationOptions.LongRunning);
// Start a background task to continuously write outgoing data
Task sending = Task.Factory.StartNew(Scenario2SendData,
streamWebSocket.OutputStream, TaskCreationOptions.LongRunning);
rootPage.NotifyUser("Connected", NotifyType.StatusMessage);
}
catch (Exception ex) // For debugging
{
if (streamWebSocket != null)
{
streamWebSocket.Dispose();
streamWebSocket = null;
}
WebErrorStatus status = WebSocketError.GetStatus(ex.GetBaseException().HResult);
switch (status)
{
case WebErrorStatus.CannotConnect:
case WebErrorStatus.NotFound:
case WebErrorStatus.RequestTimeout:
rootPage.NotifyUser("Cannot connect to the server. Please make sure " +
"to run the server setup script before running the sample.", NotifyType.ErrorMessage);
break;
case WebErrorStatus.Unknown:
throw;
default:
rootPage.NotifyUser("Error: " + status, NotifyType.ErrorMessage);
break;
}
OutputField.Text += ex.Message + "\r\n";
}
}
private async Task StartAsync()
{
// Validating the URI is required since it was received from an untrusted source (user input).
// The URI is validated by calling TryGetUri() that will return 'false' for strings that are not
// valid WebSocket URIs.
// Note that when enabling the text box users may provide URIs to machines on the intrAnet
// or intErnet. In these cases the app requires the "Home or Work Networking" or
// "Internet (Client)" capability respectively.
Uri server = rootPage.TryGetUri(ServerAddressField.Text);
if (server == null)
{
return;
}
streamWebSocket = new StreamWebSocket();
streamWebSocket.Closed += OnClosed;
// If we are connecting to wss:// endpoint, by default, the OS performs validation of
// the server certificate based on well-known trusted CAs. We can perform additional custom
// validation if needed.
if (SecureWebSocketCheckBox.IsChecked == true)
{
// WARNING: Only test applications should ignore SSL errors.
// In real applications, ignoring server certificate errors can lead to Man-In-The-Middle
// attacks. (Although the connection is secure, the server is not authenticated.)
// Note that not all certificate validation errors can be ignored.
// In this case, we are ignoring these errors since the certificate assigned to the localhost
// URI is self-signed and has subject name = fabrikam.com
streamWebSocket.Control.IgnorableServerCertificateErrors.Add(ChainValidationResult.Untrusted);
streamWebSocket.Control.IgnorableServerCertificateErrors.Add(ChainValidationResult.InvalidName);
// Add event handler to listen to the ServerCustomValidationRequested event. This enables performing
// custom validation of the server certificate. The event handler must implement the desired
// custom certificate validation logic.
streamWebSocket.ServerCustomValidationRequested += OnServerCustomValidationRequested;
// Certificate validation is meaningful only for secure connections.
if (server.Scheme != "wss")
{
AppendOutputLine("Note: Certificate validation is performed only for the wss: scheme.");
}
}
AppendOutputLine($"Connecting to {server}...");
try
{
await streamWebSocket.ConnectAsync(server);
}
catch (Exception ex) // For debugging
{
streamWebSocket.Dispose();
streamWebSocket = null;
AppendOutputLine(MainPage.BuildWebSocketError(ex));
AppendOutputLine(ex.Message);
return;
}
rootPage.NotifyUser("Connected", NotifyType.StatusMessage);
// Start a task to continuously read for incoming data
Task receiving = ReceiveDataAsync(streamWebSocket);
// Start a task to continuously write outgoing data
Task sending = SendDataAsync(streamWebSocket);
}
