Best method for storing this pointer for use in WndProc

Question

I\'m interested to know the best / common way of storing a this pointer for use in the WndProc. I know of several approaches, but each as I underst

Answer 1

With regard to SetWindowLong() / GetWindowLong() security, according to Microsoft:

The SetWindowLong function fails if the window specified by the hWnd parameter does not belong to the same process as the calling thread.

Unfortunately, until the release of a Security Update on October 12, 2004, Windows would not enforce this rule, allowing an application to set any other application's GWL_USERDATA. Therefore, applications running on unpatched systems are vulnerable to attack through calls to SetWindowLong().