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WinApi

Started by Songoku Nov 28, 2004 at 2:44 AM 3 replies 400+ views

Original Post

Nov 28, 2004 at 2:44 AM

Hi there, i have a real problem. I am improving my base code and i want to do it very well. So i first made a few design choices and got a problem. I want to create a window class which holds a function LRESULT CALLBACK WndProc(HWND....). But it does not work. Is there a way to get the windows callback funtion into a class. I want the function to be really inside the class and not to be outside the class and then to use a function pointer to the outer global windows callback funtion inside my class. Thanks for help and sorry for my bad english.

Daaark

181

Daaark

Nov 28, 2004 at 2:48 AM

There is an article on this site about doing just that. I forget what it's called, but I think it's fairly recent.

SiCrane

Mod

473

SiCrane

Nov 28, 2004 at 2:51 AM

Due to calling convention limitations, you can't assign a normal member function as the window procedure, but you can assign a static member function. That function, in turn, can call a member function after extracting a pointer from the window procedure, usually through the GWL_USERDATA flag with GetWindowLongPtr(). This data is usually assigned when handling the WM_NCCREATE message, from the LPCREATESTRUCT that is passed during window creation.

For more information, you might want to read this article.