How do I extend an existing com object?

[SunnyD]

Google is just about useless here. This is what I have:

I've become the owner of some sort of ATL COM wrapper for one of our libraries. It turns out one of our newer products wants to use it, except they found that it does not expose one of the properties that the native libraries exposes, so it's my job to fix it.

I "understand" enough about COM to trudge my way around it, but I'm a bit lost here. I'm pretty sure what I need to do is inherit the current interface and implementation as the base for a "version 2" of said object, and simply expose and implement the missing property. The problem is I'm sitting here looking at the IDL and the code for the ATL (VC6 project) and I have no idea what/where I'm looking at and where to start with all the macros and stuff Visual C uses for ATL, especially given this is all dual interface stuff.

Any suggestions would be appreciated.

 

[brandonb]

It's been about 15 years since I've done this stuff, but I know I've dealt with it way back when. I usually save my old projects in my programming folder at home on my file server (I know they date back to 1998). I can look through it later when I'm out of work and see if I can find anything for you.

Take a look at these:

http://msdn.microsoft.com/en-US/library/k9dyt26z(v=VS.80).aspx
http://www.codeguru.com/cpp/com-tech/atl/article.php/c3565/ATL-DISPID-Encoding.htm

 

[SunnyD]

Scratch that - thanks to a co-worker, I've got a workable implementation now. Google & Microsoft are mostly useless for this question, just FYI.