DL_BEGINDRAG

Overview

Group

Quick Info

Windows NT
Yes
Win95
Yes
Win32s
No
Import Library
-
Header File
commctrl.h
Unicode
No
Platform Notes
None

The DL_BEGINDRAG notification message notifies the parent window of a drag list box that the user has clicked the left mouse button on a list item. A drag list box sends DL_BEGINDRAG in the form of a drag list message.

DL_BEGINDRAG

idCtl = (int) wParam;

pDragInfo = (LPDRAGLISTINFO) lParam;

Parameters
idCtl

Control identifier of the drag list box.

pDragInfo

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

Return Values
The parent window should return TRUE to begin a drag operation or FALSE to prevent a drag operation.

Remarks
When processing this notification message, a window procedure typically determines the list item at the specified cursor position by using the LBItemFromPt function and 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.