DOC: CImageList Returned from CreateDragImage Needs Delete

MORE INFORMATION

In versions of MFC earlier than 4.2, MFC implements CreateDragImage as CImageList::FromHandle. An object returned from FromHandle is temporary and does not need to be explicitly deleted. A limitation of this implementation is that the CImageList pointer can be safely used only in the current message being processed.

CreateDragImage function was changed in Visual C++ version 4.2 to allocate a permanent CImageList object, and can now be used when handling multiple messages. When finished using the pointer returned by CreateDragImage, however, it is now necessary to explicitly delete the object:

   CImageList* pImageList = CreateDragImage( ...

   delete pImageList;
				

For more information on temporary handles returned from FromHandle, see MFC TechNote "TN003: Mapping of Windows Handles to Objects" in the Visual C++ Books Online.