_DllMain@12 already defined error

How to avoid the the following error:


mfcs42d.lib(dllmodul.obj) : error LNK2005: _DllMain@12 already defined in mydll.obj
fcs42d.lib(dllmodul.obj) : error LNK2005: __pRawDllMain already defined in mydll.obj
mfcs42d.lib(dllmodul.obj) : warning LNK4006: _DllMain@12 already defined in mydll.obj; second definition ignored
mfcs42d.lib(dllmodul.obj) : warning LNK4006: __pRawDllMain already defined in mydll.obj; second definition ignored
Creating library \Debug\mydll\mydll.lib and object \Debug\mydll\mydll.exp
\Debug\mydll\mydll.dll : fatal error LNK1169: one or more multiply defined symbols found




With the /FORCE:MULTIPLE I can build the DLL but it gives a bunch of warnings...

Thanks in advance

Xico

[Feng Yuan]

Either remove MFC or remove DllMain from your source code.

*** Appreciate good/interesting Windows graphics programming questions ***

[manoj singh]

Hello

I am getting the linker error message "_DllMain12 already defined in .obj module", when I am including <afxdb.h> file in my dll project. I cant delete DllMain from my project, because I am doing object initialisation in DllMain.

urgently seeking your help
manoj singh

[Feng Yuan]

Delete DllMain, you have to.

Move the inititialization to your CWinApp derived class' object.

*** Appreciate good/interesting Windows graphics programming questions ***

[babu1999]

Hi,
I'm also getting the same problem in case of Regular DLLs Dynamically Linked to MFC.

I get this error whenver I add


AFX_MANAGE_STATE(AfxGetStaticModuleState( ));




statement to my exported functions where MFC is used.

If I remove that statement from all exported functions NO ERROR is reported.

Pl. help.

[Feng Yuan]

Do you have your own DllMain, remove it if you're using MFC. MFC like to take it over to do some initialization.

*** Appreciate good/interesting Windows graphics programming questions ***

[babu1999]

If I write my own dllmain then do i have to call


AFX_MANAGE_STATE(AfxGetStaticModuleState( ));




function?

[Dmitriy]

DOC: AfxGetStaticModuleState() Causes Errors in an Extension DLL
Last reviewed: July 28, 1997
Article ID: Q161589
The information in this article applies to:
Microsoft Visual C++, 32-bit Edition, version 4.1


SUMMARY
The Visual C++ 4.1 MFC documentation indicates that MFC Extension DLLs need to use the macro expression "AFX_MANAGE_STATE(AfxGetStaticModuleState());" at the top of every exported DLL function. This is incorrect; MFC Extension DLLs do not need to use this expression.

This error was fixed in the documentation for Visual C++ 4.2.



MORE INFORMATION
Under the subheading "Extension DLLs" of the article "Visual C++ Books -> MFC 4.2 -> Programming with MFC:Encyclopedia - > Dynamic-Link Libraries (DLLs) -> Dynamic-Link Libraries (DLLs)," the following text appears:


"If you have a resource in your DLL, such as a dialog, you need to use
the macro AFX_MANAGE_STATE to switch the MFC module state correctly, so
that Windows looks in the DLL and not in the EXE for the resource. This
can be done by adding the following line of code to the beginning of
functions exported from the DLL:

AFX_MANAGE_STATE(AfxGetStaticModuleState( ))"


This is incorrect. Extension DLLs do not need to add this macro at the top of every exported function . The AFX_MANAGE_STATE macro can be used inside of callbacks or custom window procedures to properly adjust the current module state, but it should be used with AfxGetAppModuleState() or a specific module state instance instead of AfxGetStaticModuleState().
Any attempt to use AfxGetStaticModuleState( ) in an Extension DLL will result in possible run-time problems and the following linker errors:


"mfcs40d.lib(dllmodul.obj) : error LNK2005: __pRawDllMain already
defined in testdll1.obj
mfcs40d.lib(dllmodul.obj) : error LNK2005: _DllMain@12 already defined
in testdll1.obj
mfcs40d.lib(dllmodul.obj) : warning LNK4006: __pRawDllMain already
defined in testdll1.obj; second definition ignored
mfcs40d.lib(dllmodul.obj) : warning LNK4006: _DllMain@12 already defined
in testdll1.obj; second definition ignored"


The incorrect paragraph was removed from the documentation for Visual C++ in version 4.2.

Keywords : MfcDLL
Technology : kbInetDev
Version : 4.10
Platform : NT WINDOWS
Issue type : kbdocerr
Solution Type : kbdocfix



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Last reviewed: July 28, 1997
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Have a nice day!

[zilongcsdn]

This issue seems you redefined dllmain function, however, you not.
The way to fix it is just to put mfc42u.lib and mfcs42u.lib front of msvcrt.lib and msvcprt.lib in VC++ project setting.