Late binding to a library with “extern” defined variables

Question

I'm trying to late bind my program to a DLL.
I know how to import its methods but in one its header files, I have a definition like this:

EXTERN_C const IID SomeVariable;

How can I refer to this variable in my program without getting the "unresolved external symbol" error?

Answer 1

You can use GetProcAddress to get the address of a function or variable.

Answer 2

See GetProcAddr() at MSDN.

const IID *idp = reinterpret_cast<const IID *>(GetProcAddr(hLibrary, "SomeVariable"));

Now you can refer to SomeVariable via the pointer - just like you can refer to the functions through their pointers. You should, of course, check that the pointer is not null before you actually use it!