I'm trying to add DLLRegisterServer and DLLUnregisterServer entry points to an existing DLL that is exporting other functions. I have the olectl.h header included and here is the code I'm using to export the functions
EXTERN_C _declspec(dllexport) HRESULT STDAPICALLTYPE DllRegisterServer(void);
EXTERN_C _declspec(dllexport) HRESULT STDAPICALLTYPE DllUnregisterServer(void);
And here are the errors I get:
1> : error C2375: 'DllRegisterServer' : redefinition; different linkage
1> C:Program FilesMicrosoft Visual Studio 8VCPlatformSDKincludeolectl.h(419) : see declaration of 'DllRegisterServer'
1> : error C2375: 'DllUnregisterServer' : redefinition; different linkage
1> C:Program FilesMicrosoft Visual Studio 8VCPlatformSDKincludeolectl.h(420) : see declaration of 'DllUnregisterServer'
Can anyone tell me what I'm doing wrong with these exports?
【解决方法】
You'll have to define them (not declare them) in a source code file that doesn't #include <olectl.h>. However, COM components usually use a .def file to export entries since there are only four of them. That allows you to omit the __declspec and avoid the error. Make it look like this:
EXPORTS
DllCanUnloadNow @1 PRIVATE
DllGetClassObject @2 PRIVATE
DllRegisterServer @3 PRIVATE
DllUnregisterServer @4 PRIVATE