C++ Global Variable

watson · #1 07-23-2010, 11:53 PM

I'm working on the project (that I didn't write) and I'm stumped by the following.

First off, there's a struct that contains names of API loaded dynamically. Something like this:

Code:

typedef struct _DYN_DLL_PROC{
	FARPROC pfnDwmIsCompositionEnabled;
	//And so on
}DYN_DLL_PROC *LPDYN_DLL_PROC;

Then there's a global variable declared in the cpp file where CWinApp-derived class resides (right next to where MFC puts declaration for its own theApp variable):

Code:

DYN_DLL_PROC fns;

This struct is loaded from within the CWinApp-derived class constructor as such:

Code:

fns.pfnDwmIsCompositionEnabled = GetProcAddress(hDWMApi, "DwmIsCompositionEnabled");

But what happens is that when that API is intended to be used later on from CDialog-derived class fns.pfnDwmIsCompositionEnabled still appears as NULL! I checked the loading process above and it does not return NULL. What can be the issue here?