Need some help converting Delphi interface definitions into C++ for VS 2008

[dc_2000]

I'm curious if there're any Delphi developers here, and also people who know COM better than I do? Yeah, I know, quite a mix hah

Anyway, my goal is to call a Shell interface described here, which unfortunately is written in Delphi. I need to convert it to run in my Visual Studio 2008 C++/MFC project.

I did my best at rewriting it for VS 2008, but I'm obviously missing something because the code crashes (and I know that the Delphi equivalent works.)

I'm attaching my small demo project. Can someone take a look?

[moffy]

Since it is a COM object, can't you already use and call it from any C++ program? Or are you rewritting it because you need to modify its behaviour? You could always do the mods in Delphi, it's nice and easy to learn.

[dc_2000]

Since it is a COM object, can't you already use and call it from any C++ program?

How do I do that?

[moffy]

I can't remember the details offhand but if you read up about COM in windows/Visual Studio it will have the details. As long as the COM object is registered on the PC you can access it through its interfaces. Perhaps someone else more familiar can provide the details?

[OReubens]

I can't remember the details offhand but if you read up about COM in windows/Visual Studio it will have the details. As long as the COM object is registered on the PC you can access it through its interfaces. Perhaps someone else more familiar can provide the details?

if it's in C++, it doesn't have to be registered, you can access/use non-registered COM objects in C++ easily, other languages typically don't support this at all.

Possible ways to access COM in C++ (from easier to harder):
- For Vc++, the easy way out is to use #import to "load" the COM dll/exe and (hidden) create the appropriate include files for the compiler.
- Creating the class wrappers explicitely with ATL or MFC (or one of the many support libraries that do this as well)
- A bit harder is using the raw COM interfaces for which you'll need a c++ header.
- And of course, if the COM object supports IDispatch, use the "scripting approach" to access the COM interfaces.

[Arjay]

You can easily create COM wrapper with ATL. Read up on it in these books:

http://www.amazon.com/Beginning-ATL-.../dp/1861001207
http://www.amazon.com/Professional-A.../dp/1861001401

[2kaud]

You can easily create COM wrapper with ATL.

I guess our definition of 'easy' differs somewhat!

[Arjay]

I guess our definition of 'easy' differs somewhat!

Compared to trying to create a wrapper with MFC, ATL is easy.

[OReubens]

creating an explicit wrapper is just as easy with ATL as it is with MFC (and just as easy as FlexCOM)
USING the wrappers, dpends on the situation
if you already have an MFC project, the MFC wrapper will integrate easier. If you're not already using MFC, then going the MFC route is not advised.
setting up the ATL wrappers takes a bit of pushing and prodding in the project properties.

But it's still easier to do it this way than doign COM with the raw interfaces.

[Arjay]

If you're not already using MFC, then going the MFC route is not advised.
setting up the ATL wrappers takes a bit of pushing and prodding in the project properties.

It's even easier than that. Just open the new class dialog, select ATL under Visual C++ and choose "Add ATL Support To MFC". That sets up the MFC project for using ATL, then you can import and or create object.s