unresolved external symbol when link with exp lib

[JD]

Hi,
I am using VS.NET 2003 with MFC7 and I have a link error:
I use a library dll built with VC60 and mfc4.2, I have the export lib and
include file for that library. The dll implements a Document class (CMyDoc).
In the program when I use RUNTIME_CLASS(CMyDoc) to call CreateObject I got a
link error unresolved external symbol:
"public: static struct CRuntimeClass * __stdcall CMyDoc::GetThisClass(void)"
(?GetThisClass@CMyDoc@@SGPAUCRuntimeClass@@XZ).
I can't call CMyDoc::_GetBaseClass() instead, because it is declared
protected.
I changed the program to use _RUNTIME_CLASS(CMyDoc) instead, and I have a
different unresolved external symbol:
"public: static struct CRuntimeClass const CMyDoc::classCMyDoc"
(?classCMyDoc@CMyDoc@@2UCRuntimeClass@@B)
I know that CMyDoc::classCMyDoc is an export in my dll.

The MFC it's getting worst and worst!

[Ronald Laeremans [MSFT]]

Hi JD,

You cannot use multiple versions of MFC together in this way. While you can
use multiple versions of the MFC libraries together in one process if you
never pass any MFC objects across DLL boundaries, that is what you are
trying to do here. Neither the object layout, nor the API is compatible
between versions. You will have to rebuild the library with the 7.1 version
of MFC as well.

Ronald Laeremans
Visual C++ team

"JD" <JD@nospam> wrote in message
news:%2****************@TK2MSFTNGP09.phx.gbl...

Hi,
I am using VS.NET 2003 with MFC7 and I have a link error:
I use a library dll built with VC60 and mfc4.2, I have the export lib and
include file for that library. The dll implements a Document class
(CMyDoc).
In the program when I use RUNTIME_CLASS(CMyDoc) to call CreateObject I got
a
link error unresolved external symbol:
"public: static struct CRuntimeClass * __stdcall
CMyDoc::GetThisClass(void)"
(?GetThisClass@CMyDoc@@SGPAUCRuntimeClass@@XZ).
I can't call CMyDoc::_GetBaseClass() instead, because it is declared
protected.
I changed the program to use _RUNTIME_CLASS(CMyDoc) instead, and I have a
different unresolved external symbol:
"public: static struct CRuntimeClass const CMyDoc::classCMyDoc"
(?classCMyDoc@CMyDoc@@2UCRuntimeClass@@B)
I know that CMyDoc::classCMyDoc is an export in my dll.

The MFC it's getting worst and worst!