从MFC调用ATL COM dll

Question

I've written a com dll using VS2012. I got 2 projects - my DLL project and a PS Project. PS has 3 classes: myproj_i.h myProj_i.c myProj_p.c

now I want to call the dll from another MFC project:

hr = CoCreateInstance( CLSID_MYTASK, NULL, CLSCTX_INPROC_SERVER, IID_IMYTASK, (void**) &pMYTASK );

I have included the myproj_i.h file - so I get all the symbols recognised, yet I can't link them, as I'm missing the _i.c file.

If I add them to the project I get planty of PCH errors.

How should I Link my MFC project and call the DLL ?

I have also tried to use #import of the dll but then I get missing TLH error, and I haven't found that file in the DLL project.

Including the myProjPS.lib did not solve it either...

Answer 1

MIDL-generated .c files do not use precompiled headers. If you link them into your program (I usually make static libs of them, but that's a different method), you need to turn OFF precompiled headers for those specific .c files.

• Right-click the myProj_i.c file in the soluton explorer and bring up its properties.
• Select All Platforms/All configurations in the top two drop lists.
• Expand the C++ Settings in the left tree.
• Select Precompiled Headers in the left tree
• Switch them OFF for that file.

That should allow it to compile and link successfully.