Re: Connection Points problem

From:

"Igor Tandetnik" <itandetnik@mvps.org>

Newsgroups:

microsoft.public.vc.atl

Date:

Thu, 3 May 2007 08:17:12 -0400

Message-ID:

<OtS83zXjHHA.4188@TK2MSFTNGP02.phx.gbl>

"Rohit Kumar" <RohitKumar@discussions.microsoft.com> wrote in message
news:7DFFEDD1-DB27-4509-BDF6-DF41348993EE@microsoft.com

Following is an example of creating an ATL dll with connection points.
http://www.codeproject.com/com/connectionpoint.asp

As per the funda of connection points our client can continue its
processing without waiting for the result. After the service finishes
its computation it calls Fire_ExecutionOver(). I have putting a
messagebox in Fire_ExecutionOver().
Now as per below code, after call to Add(), i can continue with my
processing. So i put another messagebox after Add(). But the problem
i am facing is that after the call to add the client gets hanged up
waiting for the result and does not proceed untill the server calls
Fire_ExecutionOver().

The article generates unrealistic expectations. For the idea to work,
Add() must initiate some background processing and return immediately.
When the processing is complete, event is fired to let the client know.
The way it's actually done in the article is completely pointless: Add()
performs the processing itself (simulated with a Sleep call), then fires
the event right before returning. This doesn't help the client in the
slightest.

Just the presence of connection point doesn't magically turn a
synchronous COM call into an asynchronous one.
--
With best wishes,
Igor Tandetnik

With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925