Subclassing in C++

When I hear people talking about using VB to subclass windows that arent yours, they say you need a C++ DLL,
but I heard somebody say on this forum that you still need a DLL to do it in C++....


is there ANY WAY to subclass any window in C++ without using a DLL???


Thanks,

Dennis

[Sam Finch]

Nope. The reason you need a dll is that the foreign procedure can't access the memory of a standard exe. but it can get at the memory in a standard dll. It's not too hard, just make the dll to subclass it (put in all the stuff you'd put in a standard module in VB) then call the functions in the dll. windows will automaticly inject the dll into the foreign procedure.

Ok, I see now....
How would I go about doing that?
would I have to have a specific DLL for each thing I want to subclass?
or could I just have a universal one???

and on the subject of DLL's. how do you make one?
I tried making a simple message box DLL, but when I tried to use it from VB it said that it couldnt find the DLL entry point.

[parksie]

Some function names are a bit dodgy - what name did you use for your function?

You can call the built-in SubClass routine.

CTestDlg dlg;
dlg.SubclassWindow(m_hWnd);

Parksie, I named the function MsgBBox.


Megatron, is that part of MFC??
because I dont want to use MFC.

[parksie]

I think that's only for MFC.

Dennis - you can't create standard DLLs in VB - you have to use C++ or another language that makes them. Also, make a .def file, with this in it:

LIBRARY yourdll.dll

DESCRIPTION 'My DLL'

EXPORTS
	Function_A
	Different_function

Add it to your project, and it should work...

I know I cant create standard DLL's in VB, I was talking about in C++,
I made one with a fucntion of MsgBBox, and when i tried accessing it from vb, It said it couldnt find the DLL entry point.

[parksie]

You need to specifically export the function. This is for VC++:

__declspec(dllexport) long MsgBBox(HWND hWnd, ...) {
    return 0;
}

then put this into the .def file, which tells the DLL creation process what to export:

LIBRARY yourdll.dll

DESCRIPTION 'My DLL'

EXPORTS
	MsgBBox

If you add it to your project, it will export the named functions.