Win8 C＃ - UDP监听器和线程停止

Question

我遇到用C＃编写的Win8 metro应用程序的问题。我有UDP侦听器，它从WP7设备接收数据包（简单的一个字符串命令）。

我可以看到数据包正在进入应用程序，但我只能接收其中几个。在输出窗口中一段时间​​（5-10秒）后我收到

  

线程0x5a4已退出，代码为0（0x0）。

我不明白为什么线程会停止。这是我的源代码，非常简单。我绑定了监听器，设置事件处理程序，然后当我收到命令时，我只是在UI上移动椭圆形状（用户）。

代码：

private async void Button_Click_1(object sender, RoutedEventArgs e)
{
    DatagramSocket listener = new DatagramSocket();          
    listener.MessageReceived += listener_MessageReceived;            

    try
    {
        await listener.BindServiceNameAsync(serviceName.Text);            
    }
    catch (Exception exception)          
    {               
        if (SocketError.GetStatus(exception.HResult) == SocketErrorStatus.Unknown)
        {
            throw;
        }                
    }                
}

async void listener_MessageReceived(DatagramSocket socket, DatagramSocketMessageReceivedEventArgs eventArguments)
{
    try
    {
        uint stringLength = eventArguments.GetDataReader().UnconsumedBufferLength;
        string command = eventArguments.GetDataReader().ReadString(stringLength);

        await this.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
            {
                MessageBlock.Text = "Message : " + command + " (@ " + DateTime.Now;
                MakeMove(command); 
            }
        );            
    }
    catch (Exception exception)
    {
        SocketErrorStatus socketError = SocketError.GetStatus(exception.HResult);
        if (socketError == SocketErrorStatus.ConnectionResetByPeer)
        {                     
            Debug.WriteLine("Peer does not listen on the specific port. Please make sure that you run step 1 first " +
                        "or you have a server properly working on a remote server."); 
        }
        else if (socketError != SocketErrorStatus.Unknown)
        {
            Debug.WriteLine("Error happened when receiving a datagram: " + socketError.ToString());
        }
        else
        {
            throw;
        }
    }
}

private void MakeMove(string command)
{
    Debug.WriteLine(command);

    switch (command)
    {
        case "10":
            this.user.SetValue(Canvas.TopProperty, Convert.ToInt32(this.user.GetValue(Canvas.TopProperty)) - 50);
            break;
        case "20":
            this.user.SetValue(Canvas.LeftProperty, Convert.ToInt32(this.user.GetValue(Canvas.LeftProperty)) + 50);
            break;
        case "30":
            this.user.SetValue(Canvas.TopProperty, Convert.ToInt32(this.user.GetValue(Canvas.TopProperty)) + 50);
            break;
        case "40":
            this.user.SetValue(Canvas.LeftProperty, Convert.ToInt32(this.user.GetValue(Canvas.LeftProperty)) - 50);
            break;
        case "50":
            this.user.SetValue(Canvas.LeftProperty, Convert.ToInt32(this.user.GetValue(Canvas.LeftProperty)) + 50);
            this.user.SetValue(Canvas.TopProperty, Convert.ToInt32(this.user.GetValue(Canvas.TopProperty)) - 50);
            break;
        case "60":
            this.user.SetValue(Canvas.LeftProperty, Convert.ToInt32(this.user.GetValue(Canvas.LeftProperty)) - 50);
            this.user.SetValue(Canvas.TopProperty, Convert.ToInt32(this.user.GetValue(Canvas.TopProperty)) - 50);
            break;
        case "70":
            this.user.SetValue(Canvas.LeftProperty, Convert.ToInt32(this.user.GetValue(Canvas.LeftProperty)) + 50);
            this.user.SetValue(Canvas.TopProperty, Convert.ToInt32(this.user.GetValue(Canvas.TopProperty)) + 50);
            break;
        case "80":
            this.user.SetValue(Canvas.LeftProperty, Convert.ToInt32(this.user.GetValue(Canvas.LeftProperty)) - 50);
            this.user.SetValue(Canvas.TopProperty, Convert.ToInt32(this.user.GetValue(Canvas.TopProperty)) + 50);
            break;
        default:
            Debug.WriteLine("Unknown command");
            break;
    }

我做错了什么？

提前谢谢！