HDN_BEGINDRAG notification code
Sent by a header control when a drag operation has begun on one of its items. This notification code is sent only by header controls that are set to the HDS_DRAGDROP style. This notification code is sent in the form of a WM_NOTIFY message.
A pointer to an NMHEADER structure containing information about the header item that is being dragged.
To allow the header control to automatically manage drag-and-drop operations, return FALSE. If the owner of the control is manually performing drag-and-drop reordering, return TRUE.
A header control defaults to automatically managing drag-and-drop reordering. Returning TRUE to indicate external (manual) drag-and-drop management allows the owner of the control to provide custom services as part of the drag-and-drop process.
Minimum supported client
|Windows Vista [desktop apps only]|
Minimum supported server
|Windows Server 2003 [desktop apps only]|