PRB: Shell Returns DROPEFFECT_NONE Instead of DROPEFFECT_MOVE

ID: Q182219

The information in this article applies to:

Microsoft Win32 Software Development Kit (SDK)
Microsoft Windows NT 4.0
Microsoft Windows 2000

SYMPTOMS

When a file is moved onto a shell window in Windows NT 4.0 through OLE Drag- and-Drop and the CF_HDROP format, DoDragDrop returns DROPEFFECT_NONE instead of DROPEFFECT_MOVE, even though the file is successfully moved.

CAUSE

The Windows NT 4.0 shell optimizes the move operation by moving the file itself. A return value of DROPEFFECT_MOVE tells the calling program that it should delete the file itself. However, since the shell has already done this, it returns DROPEFFECT_NONE.

RESOLUTION

If the originating program needs to know if the file actually was moved, it can check to see if the source file still exists.

Windows 95 also performs this optimized move, but returns DROPEFFECT_MOVE.

STATUS

This behavior is by design.

Additional query words:

Keywords : kbDragDrop kbNTOS400 kbWinOS2000 kbSDKWin32 kbGrpShell
Version : WINDOWS:; winnt:4.0
Platform : WINDOWS winnt
Issue type : kbprb