HDN_BEGINTRACK notification code
Notifies a header control's parent window that the user has begun dragging a divider in the control (that is, the user has pressed the left mouse button while the mouse cursor is on a divider in the header control). This notification code is sent in the form of a WM_NOTIFY message.
HDN_BEGINTRACK
pNMHeader = (LPNMHEADER) lParam;
Parameters
-
lParam
-
A pointer to an NMHEADER structure that contains information about the header control and the item whose divider is to be dragged.
Return value
Returns FALSE to allow tracking of the divider, or TRUE to prevent tracking.
Requirements
Requirement | Value |
---|---|
Minimum supported client |
Windows Vista [desktop apps only] |
Minimum supported server |
Windows Server 2003 [desktop apps only] |
Header |
|
Unicode and ANSI names |
HDN_BEGINTRACKW (Unicode) and HDN_BEGINTRACKA (ANSI) |