This message is sent to the source of a drag operation immediately after a DM_DRAGOVER message is sent to a target window.

param2 is the target's reply to the DM_DRAGOVER message.

param1
     PDRAGINFO  pDraginfo    /*  Pointer to the DRAGINFO structure that represents the object being dragged. */

param2
     USHORT     usDrop       /*  Drop indicator. */
     USHORT     usDefaultOp  /*  Default operation. */