I am making a C program which should use an ActiveX control.
I have an ActiveX control and i know its CLSID, I want to use it so I do :
hr = CoInitializeEx ( NULL, COINIT_MULTITHREADED );
hr = CoCreateInstance ( &clsid,
&IID_IUnknown, //(REFIID) &giid,
If I do so ... I have a link error LNK2001 telling me : unresolved external symbol IID_IUnknown
When I am using an ActiveX control is it a proper manner user IID_IUnknown as the REFIID, if not what should i use as the REFIID and how do I define it.