Deleting a Window Property

When a window is destroyed, it must destroy any window properties it set. The following example uses the EnumPropsEx function and the application-defined callback function DelPropProc to destroy the properties associated with the window identified by the application-defined hwndSubclass variable. The callback function, which uses the RemoveProp function, is also shown.

case WM_DESTROY: 
 
    EnumPropsEx(hwndSubclass, DelPropProc, NULL); 
 
    PostQuitMessage(0); 
    break; 
 
// DelPropProc is an application-defined callback function 
// that deletes a window property. 
 
BOOL CALLBACK DelPropProc( 
    HWND hwndSubclass,  // handle of window with property 
    LPCSTR lpszString,  // property string or atom 
    HANDLE hData)       // data handle 
{ 
    RemoveProp(hwndSubclass, lpszString); 
 
    return TRUE; 
}