mfcs80ud.lib(dllmodul.obj) : error LNK2005: _DllMain@12 already defined in MSVCRTD.lib(dllmain.obj)

To solve it, do the following steps:

1.    Open project property pages by Alt+F7

2.    Navigate to Configuration properties->Linker->Input section.

3.    Add msvcrtd.lib; mfcs80ud.lib to theIgnore specific library.

4.    Add mfcs80ud.lib msvcrtd.lib to theAdditional dependencies.

Now we will tell you how to find out these two disorder libraries. In the project property pages, navigate to configuration properties->linker->command line, add /verbose:libto the additional option. Rebuild your project, and look carefully to the output window, you will find that is mfcs80ud.lib generated the link error, look before mfcs80ud.lib, you will find there is only one CRT library before it, so ignore these 2 libraries in the Ignore specific library, then add them in the additional dependencies with right order. Rebuild again, it should works.

PS.visual studio2005下dll为80,2010下100.上面讲的是在Visual Studio 2005下的情况，VS2010下雷同。