c# - 如何使用 MSMQ 发送/接收多播消息？

Question

有人可以帮我找到一些示例代码，以使用您选择的任何 .NET 语言使用 MSMQ 发送和接收 Multicast 消息。我四处搜索了一下，看到发送的是:

MessaegQueue topic = new MessageQueue("formatname:multicast=234.1.1.1:8081")
topic.Send("Hello out there")

我试着用 Receive 做同样的事情:

MessageQueue topic = new MessageQueue("formatname:multicast=234.1.1.1:8081")
topic.Receive();

但我一无所获。谁能展示一些关于如何接收多播消息的示例代码？还是我发错了？

Answer 1

所以我想通了。

发送多播消息:

MessageQueue topic = new MessageQueue("formatname:multicast=234.1.1.1:8081")
topic.Send("Hello out there")

接收多播消息:

这有点棘手，因为您无法订阅多播地址。您需要做的是创建一个队列，最好是创建一个私有(private)队列，该队列将附加到您要监视的多播地址，然后监听您创建的私有(private)队列而不是多播地址。像这样:

  Dim privMulticastQueue As String = GetPrivateQueueForMulticastAddress("formatname:multicast=234.1.1.1:8081")
  Dim msgq as MessageQueue = GetMessageQueue(privMulticastQueue)
  msgq.MulticastAddress = GetMulticastAddress(destination)
  msgq.Label = "Private Queue for receiving messages from: " & destination
  msgq.Receive()

还有一些支持方法(可能有更好的写法，欢迎指正，但这是我的第一次尝试):

 Private Function GetPrivateQueueForMulticastAddress(ByVal dest As String) As String
    Dim privateQ As String = GetMulticastAddress(dest).Replace(".", "_").Replace(":", "_")
    Return ".\Private$\" & privateQ
 End Function

Private Function GetMulticastAddress(ByVal dest As String) As String
    Return dest.Split("=")(1)
End Function

Private Function GetMessageQueue(ByVal dest As String) As MessageQueue   
      Try
           If Not MessageQueue.Exists(dest) Then
             MessageQueue.Create(dest)
            End If

            Dim msgq As MessageQueue = New MessageQueue(dest)
            Return msgq
      Catch ex As Exception
            Throw New EMGException("Failed while trying to use destination: " & dest, ex)
      End Try

End Function