Re: Connection Point for interfaces

From:
"Igor Tandetnik" <itandetnik@mvps.org>
Newsgroups:
microsoft.public.vc.atl
Date:
Thu, 4 May 2006 08:45:36 -0400
Message-ID:
<O3Sqki3bGHA.3472@TK2MSFTNGP02.phx.gbl>
"Andrey" <andrej@telemed.lt> wrote in message
news:%23%237h0a3bGHA.536@TK2MSFTNGP02.phx.gbl

Let me describe my requirements. Probably you know standard solution.
I want to implement object that supports connection points. And I want
managed languages "see" that connection point as events. But this
object is not coclass object (in my opinion). I meen that this object
can't be created
using CoCreateInstance function call. It can be only retrieved from
other objects. Does it is possible?


I know VB can support this, I don't know about C# or other .NET
languages. You still need to define a coclass in the IDL, you can mark
it with [noncreatable] attribute. Then in VB you do something like this:

Dim WithEvents myObj As MyCoclass
Set myObj = otherObj.CreateMyObj

Now you can handle events in the usual way, with Sub myObj_EventName.

I think in C# you can do something like

MyCoclass myObj;
myObj = otherObj.CreateMyObj();
myObj.EventName += new EventNameDelegator(EventHandler);

(very rough and approximate syntax, I'm really not fluent in C#).

BTW. I have found in documentation that [source] attribute can be used
not only with coclass statement, but with methods and properties. But
can't to find example of such [source] attributes usage. Do you know
such samples?


Now that you mention it, I see it in the documentation too, but I've
never seen this usage in practice and I have no idea how this is
supposed to work, nor what it might be useful for.
--
With best wishes,
    Igor Tandetnik

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necessarily a good idea. It is hard to be sure where they are going to
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