What is the lifetime of a CWnd obtained from CWnd::FromHandle?
问题 According to msdn, when I get a CWnd* with CWnd::FromHandle, The pointer may be temporary and should not be stored for later use. What is meant by "later use" is not clear to me. Is it only the scope of the current method? As far as I know, there is no GC in Win32! 回答1: MFC maintains a number of handle maps, from HWND to CWnd, HDC to CDC etc, which are stored in the thread state. Each handle map contains a permanent map and temporary map - permanent entries are added when you call a method