The calling thread can not access this object because it belongs to a different thread

Follow the code:

private async void button_1_Click(object sender, RoutedEventArgs e)
{    
    var listenPort = 11000;
    var listener = new TcpSocketListener();
    listener.ConnectionReceived += async (senders, args) =>
    {
        var client = args.SocketClient;
        var reader = new StreamReader(client.ReadStream);
        var data = await reader.ReadLineAsync() + "n";

        var split = data.Split('#');

        button_proximo.RaiseEvent(new RoutedEventArgs(System.Windows.Controls.Primitives.ButtonBase.ClickEvent));

        var bytes = Encoding.UTF8.GetBytes(data);
        await client.WriteStream.WriteAsync(bytes, 0, bytes.Length);
        await client.WriteStream.FlushAsync();
    };

    await listener.StartListeningAsync(listenPort);
}

The error I get:

  

System.InvalidOperationException: ‘The calling thread can not
  access this object because it belongs to a different thread. ‘

This error happens only within ConnectionReceived , if I put the line button_proximo.RaiseEvent(new RoutedEventArgs(System.Windows.Controls.Primitives.ButtonBase.ClickEvent)); out of ConnectionReceived it works normal.

Any solution?

You have to access the interface components in the same thread where they were created (also known as the UI thread). To do this you can dispatcher . Example:

Application.Current.Dispatcher.BeginInvoke(
  DispatcherPriority.Background,
  new Action(() => 
    button_proximo.RaiseEvent(new RoutedEventArgs(System.Windows.Controls.Primitives.ButtonBase.ClickEvent));
);