Project 98: Subclass Window == Access Violation.

[msmith]

G'day

I'm working on a security application. One of the things it does is
to subclass any window that is accepting "dropped files" (i.e. calls
DragAcceptFiles(hWnd, TRUE)).

This seems to work fine for most applications, but not Project 98. As
soon as the window is subclassed, it gives an Access Violation.

Even if I trap the WindowsProc using GetWindowLongPtr(hWnd,
GWLP_WNDPROC) and the SetWindowLongPtr to insert my Window proc (which
on-calls the old window proc using CallWindowProc()), Project still
gives an immediate Access Violation.

Has anybody else seen this happen? Any ideas on how to get 'round it?

I can't imagine what Project is doing that will blow up as soon as you
fiddle with the window proc.

I'm using VC++ 2002, in case that matters.

Regards

Michael J