DM DROPHELP
This message requests help for the current drag operation.
Syntax
param1 PDRAGINFO pDraginfo; /* Pointer to the DRAGINFO structure used in the drag operation. */ param2 ULONG ulReserved; /* Reserved value, should be 0. */
Parameters
- pDraginfo (PDRAGINFO) - Input
- Pointer to the DRAGINFO structure used in the drag operation.
- ulReserved (ULONG) - Input
- Reserved value, should be 0.
Returns
- ulReserved (ULONG) - returns
- Reserved value, should be 0.
Remarks
This message is posted to the target of a drop when F1 is pressed during a direct-manipulation operation, and the drag operation is canceled.
The usOperation field of pDraginfo can be used to provide help information in the context of the drag operation during which it was requested.
The DM_DROPHELP message is not supported for lazy drag operations. Since the drag operation is non-modal, the user may request help on anything at any time during the drag. If the application wishes to provide drop help, it must specify the action required to invoke drop help (for example, a menu choice) and code the support for it explicitly.
Default Processing
The WinDefWindowProc function calls DrgDeleteDraginfoStrHandles and DrgFreeDraginfo for pDraginfo and returns 0.