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DL_BEGINDRAG notification code

  • Artikkeli

Notifies the drag list box's parent window that the user has clicked the left mouse button on an item. A drag list box sends this notification code in the form of a drag list message. For more information, see Drag List Box Messages.

DL_BEGINDRAG

    pDragInfo = (LPARAM)(LPDRAGLISTINFO) lParam;

Parameters

lParam

A pointer to a DRAGLISTINFO structure that contains the DL_BEGINDRAG notification code, the handle to the drag list box, and the cursor position.

Return value

Return TRUE to begin the drag operation, or FALSE to prevent the drag operation.

Remarks

When processing this notification code, a window procedure typically determines the list item at the specified cursor position by using the LBItemFromPt function. It then returns TRUE or FALSE, depending on whether the item should be dragged. Before returning TRUE, the window procedure should save the index of the list item so the application knows which item to move or copy when the drag operation is completed.

Requirements

Requirement Value
Minimum supported client
 Windows Vista [desktop apps only]
Minimum supported server
 Windows Server 2003 [desktop apps only]
Header
Commctrl.h