UWP DatagramSocket組播

Question

我設法制作了一個簡單的應用程序，用於發送和接收來自多播組的數據。如果我打開應用程序的2個實例（2個不同的.sln文件具有相同的代碼），我可以發送和接收數據。問題是，5秒後，如果我從Client001發送消息，則只有Client001會收到消息。但是，如果我在5秒內從Client002（應用程序的第二個實例）發送消息，那麼它們都會收到消息。 我有一個使用UdpClient的例子，它可以很好地工作，但不再適用於UWP。 所以總而言之，無論何時（不是在5秒鐘內）某些客戶端發送消息，所有其他客戶端都得到它？

這是MainPage.xaml.cs中

namespace Client001 
{ 
    /// <summary> 
    /// An empty page that can be used on its own or navigated to within a Frame. 
    /// </summary> 
    public sealed partial class MainPage : Page 
    { 
     private DatagramSocket listenerSocket = null; 
     public string remoteAddress = "224.3.0.5"; 
     HostName remoteHostname; 
     public string serviceName = "22113"; 
     IOutputStream outputStream; 
     DataWriter writer; 

     public MainPage() 
     { 
      this.InitializeComponent(); 
      SetupMulticastScenarioUI(); 

      remoteHostname = new HostName(RemoteAddress.Text); 
     } 

     private void CloseListenerSocket() 
     { 
      if (listenerSocket != null) 
      { 
       // DatagramSocket.Close() is exposed through the Dispose() method in C#. 
       // The call below explicitly closes the socket, freeing the UDP port that it is currently bound to. 
       listenerSocket.Dispose(); 
       listenerSocket = null; 
      } 
     } 

     // Sets up the UI to display the multicast scenario options. 
     private void SetupMulticastScenarioUI() 
     { 
      RemoteAddress.Text = remoteAddress; 
      ServiceName.Text = serviceName; 
      StartListener.Content = "Start listener and join multicast group"; 
      SendMessageButton.IsEnabled = false; 
      CloseListenerButton.IsEnabled = false; 
      SendOutput.Text = ""; 
     } 

     private async void StartListener_Click(object sender, RoutedEventArgs e) 
     { 
      listenerSocket = new DatagramSocket(); 

      listenerSocket.Control.MulticastOnly = true; 
      await listenerSocket.BindServiceNameAsync(ServiceName.Text); 

      // Join the multicast group to start receiving datagrams being sent to that group. 
      listenerSocket.JoinMulticastGroup(remoteHostname); 

      listenerSocket.MessageReceived += MessageReceived; 
      SendOutput.Text = "Listening on port " + listenerSocket.Information.LocalPort + " and joined to multicast group"; 

      // Enable scenario steps that require us to have an active listening socket. 
      SendMessageButton.IsEnabled = true; 
      CloseListenerButton.IsEnabled = true; 

      outputStream = await listenerSocket.GetOutputStreamAsync(remoteHostname, ServiceName.Text); 
      writer = new DataWriter(outputStream); 
      writer.WriteString("Handshake1"); 
      await writer.StoreAsync(); 
     } 

     private async void SendMessage_Click(object sender, RoutedEventArgs e) 
     { 
      writer.WriteString(Message.Text); 
      await writer.StoreAsync(); 
     } 

     private void CloseListener_Click(object sender, RoutedEventArgs e) 
     { 
      CloseListenerSocket(); 

      // Disable scenario steps that require us to have an active listening socket. 
      SendMessageButton.IsEnabled = false; 
      CloseListenerButton.IsEnabled = false; 
      SendOutput.Text = ""; 

      SendOutput.Text = "Listener closed"; 
     } 

     async void MessageReceived(DatagramSocket socket, DatagramSocketMessageReceivedEventArgs eventArguments) 
     { 
      // Interpret the incoming datagram's entire contents as a string. 
      uint stringLength = eventArguments.GetDataReader().UnconsumedBufferLength; 
      string receivedMessage = eventArguments.GetDataReader().ReadString(stringLength); 

      await Dispatcher.RunAsync(CoreDispatcherPriority.Normal,() => 
      { 
       SendOutput.Text = "Received data from remote peer (Remote Address: " + 
        eventArguments.RemoteAddress.CanonicalName + ", Remote Port: " + 
        eventArguments.RemotePort + "): \"" + receivedMessage + "\""; 
      }); 
     } 
    } 
} 

代碼這是MainPage.xaml中

<Page 
    x:Class="Client001.MainPage" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    xmlns:local="using:Client001" 
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
    mc:Ignorable="d"> 


    <StackPanel> 
     <TextBlock>Remote Address:</TextBlock> 
     <TextBox x:Name="RemoteAddress" /> 

     <TextBlock>Service Name:</TextBlock> 
     <TextBox x:Name="ServiceName" /> 

     <Button x:Name="StartListener" Click="StartListener_Click" Margin="0,10,0,0"/> 
     <Button x:Name="SendMessageButton" Content="Send 'hello'" Click="SendMessage_Click" Margin="0,10,0,0"/> 
     <Button x:Name="CloseListenerButton" Content="Close Listener" Click="CloseListener_Click" Margin="0,10,0,0"/> 
     <TextBlock x:Name="SendOutput" TextWrapping="Wrap" Margin="0,10,0,0"/> 
     <TextBox x:Name="Message"></TextBox> 
    </StackPanel> 

</Page> 

UPDATE的代碼：位的後搜索我發現，也許TTL（生存時間）是問題，但我仍然不知道如何解決這個問題。

Answer 1

所以總而言之，無論何時（不是在5秒內）某些客戶端發送消息，所有其他客戶端都得到它？

看起來，這個問題已在最新的Windows RS1（建設14393） OS，這裏是截圖（GIF）：

您可能需要升級操作系統解決這個問題。