This message is sent to the window that is directly under the hot spot of the mouse pointer during the drag operation when any of the following conditions are met:

• The user moves the mouse.
  
• A key is pressed.
  
• A WM_BUTTON1UP, WM_BUTTON2UP, WM_BUTTON3UP, or WM_ENDDRAG message is received. The message corresponds to parameter specified by the call to DrgDrag indicating that the drag is ending. In this case the message is sent only if the mouse has moved since the last DM_DRAGOVER message was sent.

The receiver can gain access to the DRAGINFO structure with DrgAccessDraginfo. The acceptability of the dragged objects can be determined by querying the hstrType and hstrRMF string handles in each of the DRAGITEM structures carried in DRAGINFO structure. In order to accept the drop, the target window must be able to accept all of the objects that are being dragged.

The receiver should provide target emphasis for itself. The receiver can use DrgSetDragPointer to change the bit map while it is being dragged over. A DM_DRAGLEAVE or DM_DROP message will be sent to the target in the future. Target emphasis should be removed at that time.

If usOperation in DRAGINFO is DO_DEFAULT or DO_UNKNOWN and the target returns DOR_DROP for usDrop, usDefaultOp should be set to reflect what the target defines as the default operation. This information is used to provide the appropriate modification to the drag pointer and the target's default operation will be passed in the usOperation field of the DRAGINFO structure specified in the DM_DROP message.

If the value of the usOperation field is not DO_DEFAULT or DO_UNKNOWN, the usDefaultOp parameter is ignored.

Note: Lazy drag enabled applications are expected to process this message. It is to be handled in the same manner as the standard drag enabled applications.