Registers the specified window as one that can be the target of an OLE drag-and-drop operation and specifies the IDropTarget instance to use for drop operations.
WINOLEAPI RegisterDragDrop(
HWND hwnd, //Handle to a window that can accept drops
IDropTarget * pDropTarget
//Pointer to object that is to be target of drop
);
This function supports the standard return value E_OUTOFMEMORY, as well as the following:
If your application can accept dropped objects during OLE drag-and-drop operations, you must call the RegisterDragDrop function. Do this whenever one of your application windows is available as a potential drop target, i.e., when the window appears unobscured on the screen.
The RegisterDragDrop function only registers one window at a time, so you must call it for each application window capable of accepting dropped objects.
As the mouse passes over unobscured portions of the target window during an OLE drag-and-drop operation, the DoDragDrop function calls the specified IDropTarget::DragOver method for the current window. When a drop operation actually occurs in a given window, the DoDragDrop function calls IDropTarget::Drop.
The RegisterDragDrop function also calls the IUnknown::AddRef method on the IDropTarget pointer.
Windows NT: Use version 3.1 or later.
Windows: Use Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in ole2.h.
Import Library: Included as a resource in ole32.dll.