Async Callbacks .NET and ABL - is it possible?

Hi All,

I'm working on a program that can receive messages from MSMQ using .NET libraries (see original thread http://communities.progress.com/pcom/message/163326#163326).

I have developed a simple sender, single receiver and polling receiver programs. All working great.

I'm currently working on an asynchrous receiver that *hopefully* will process messages as they arrive in the queue - using callbacks. I'm trying to convert the C sample code in http://msdn.microsoft.com/en-us/library/hx1zzcwy%28v=vs.100%29.aspx into ABL - as a starting point.

The 'BeginReceive' method requires the AsyncCallBack class which is the method to call when a message arrives on the queue. This has one parameter (according to the sample)

 // Begin the asynchronous receive operation.
 queue.BeginReceive(TimeSpan.FromSeconds(10.0), messageNumber++,
    new AsyncCallback(MyReceiveCompleted));

However when I try to use that same method in ABL (OE 11.0), I get a compile error, Progress expects 2 parameters not one.

    /* 10 seconds */
    loTimeSpan = new System.TimeSpan(0,0,10).
   
    loAsyncCallBack = new System.AsyncCallback("MyReceiveCompleted").   /* Progress complains that 2 parameters are required */
   
    oQueue:BeginReceive(loTimeSpan,liMsgNumber,loAsyncCallBack).

Searching for the constructor for 'AsyncCallback', I find out that it is a delegate (not sure what that is) - http://msdn.microsoft.com/en-us/library/system.asynccallback.aspx

What also caught my attention (in the above URL) was this statement:

Use an AsyncCallback delegate to process the results of an asynchronous operation in a separate thread.

Sooooo, I wondering whether I can do this in ABL? Is it possible? If so, some pointers would be greatly appreciated.

I know with SonicMQ - via ABL - that you can use the methods Progress provides (string name of the call back procedure and a handle as to where that procedure is located) to do this. I am assuming something similar will be needed for .NET, just not sure how to do that!

Many thanks

David.