How do I send/receive multicast messages using MSMQ?

Question

Can someone please help me find some sample code to SEND and RECEIVE Multicast messages using MSMQ using any .NET language of your choice. I have searched around and kind of see the send being:

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

I tried to do the same idea with Receive:

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

but I get nothing. Can anyone show some sample code on how to receive multicast messages? or am I sending them wrong?

This might help: http://stackoverflow.com/questions/10435706/msmq-cannot-receive-from-multicast-queues — dbugger, Feb 27 '15 at 20:44
I stumbled on that site many times today. The explanation he gives there is very confusing but it makes perfect sense now. I used to use ActiveMQ and WebSpehere MQ which were simpler than MSMQ in terms of having topics and queues. MSMQ can do the same thing but needs a little bit of engineering to achieve the same thing. At my current company we wanted to try MSMQ. — Denis, Feb 27 '15 at 21:54

Denis · Accepted Answer · 2015-02-27T21:59:42.547

So I figured it out.

To send a multicast message:

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

To receive a multicast message:

It is a little tricky because you can't subscribe to the multicast address. What you need to do is create a queue, probably best to create a private queue that will be attached to the multicast address you want to monitor and then listen to the private queue you created INSTEAD of the multicast address. Something like this:

  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()

And some supporting methods (probably there is a better way to write them so feel free to correct but this is my first crack at it):

 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

How do I send/receive multicast messages using MSMQ?

1 Answers1

Linked