Sorry if this is a bit c++ specifc.

I have my code for mdi windows in a class which i allocate for each window using setwindowlong with GWL_USERDATA. i retrieve it in wndproc using getwindowlong. But the values of the members (hwnds,etc) in the class retrieved do not remain the same and thus my code is not working cause all the window hwnds go invalid. ;-(

Please help someone.
Posted on 2001-11-17 15:19:28 by MovingFulcrum
Possibly you are using extra bytes already used by the mdi-client or mdi-child window. Cant find any doc at the moment, but for a test just increase the amount of extra bytes to 64 and use only the last 4 bytes as a pointer to your instance data.

just inspected a mdi sample app with the spy utility. mdi child windows use NO window extra bytes, so forget my test suggestion please
Posted on 2001-11-18 03:20:07 by japheth