Re: NT service and connection points

From:
"Alexander Nickolov" <agnickolov@mvps.org>
Newsgroups:
microsoft.public.vc.atl
Date:
Wed, 18 Oct 2006 14:00:20 -0700
Message-ID:
<uYpzshv8GHA.3552@TK2MSFTNGP03.phx.gbl>
A callback interface is an interface you specify in your server
but do not implement. Connection points are just a standard
mechanism of passing [multiple] callback interfaces (called
source interfaces in this context) to the object with multicast
semantics.

A simple method for passing a single unicast callback interface
pointer to an object is:

HRESULT registerCallback([in] ICallback* pCallback);

The object accepts the callback, AddRef-s it and stores it
internally, then calls it when needed. To revoke the callback
pass NULL interface pointer to the same method.

BTW, your news client seems not to obey followup-to headers.
I removed the networking group explicitly.

--
=====================================
Alexander Nickolov
Microsoft MVP [VC], MCSD
email: agnickolov@mvps.org
MVP VC FAQ: http://www.mvps.org/vcfaq
=====================================

"MON205" <MON205@discussions.microsoft.com> wrote in message
news:67B1A244-FD2A-470D-A25B-2F0591280E13@microsoft.com...

Thanks.
But I'm not an expert in Inter Process Connections. So, what is a
"callback
interface"? Can I send parameters using it?

"Alexander Nickolov" wrote:

And what is the problem with using events to your GUI
application? You may want to structure it using a callback
interface instead of using connection points though, since
the latter may not have the correct semantics for you.

My point is, always have the application connect to your
service. Don't try to create objects in your application
from within your service. Your GUI application must
always be in control, not your service.

--
=====================================
Alexander Nickolov
Microsoft MVP [VC], MCSD
email: agnickolov@mvps.org
MVP VC FAQ: http://www.mvps.org/vcfaq
=====================================

"MON205" <MON205@discussions.microsoft.com> wrote in message
news:9DC51BFD-F6B0-480F-92AC-DED45C4C58B9@microsoft.com...

Thanks for reply.
I meant that I want the service send commands to the GUI.
.....
"Alexander Nickolov" wrote:

The correct group is:

microsoft.public.vc.atl

I set the followup to go to that group, so check for replies there.

How do you "reverse the behavior"? Why do you need to do that?

--
=====================================
Alexander Nickolov
Microsoft MVP [VC], MCSD
email: agnickolov@mvps.org
MVP VC FAQ: http://www.mvps.org/vcfaq
=====================================

"MON205" <MON205@discussions.microsoft.com> wrote in message
news:46F32526-6B5B-4670-B9EA-254EDC1C585F@microsoft.com...

Hello all,

I have an NT Service which should communicate with a desktop MFC
application. To do this communication, I used an ATL/COM server
(EXE)
with
a
simple ATL object that has an interface with connection points.
When the desktop application implements the IDispatch interface to
listen
to connection point calls, and the NT service calls the application
via
connection points; the communication run successfully. But when I
reverse
the
behavior and let the service implements the IDispatch interface and
let
the
desktop application call the service; the connection hangs in the
Fire_XXX
event.

May be this is not the suitable forum for ATL issues, but I didn't
find
a
suitable one.
can any one help please.

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