The HDN_DIVIDERDBLCLICK notification message notifies a header control's parent window that the user double-clicked the divider area of the control. This notification message is sent in the form of a WM_NOTIFY message.
HDN_DIVIDERDBLCLICK
phdn = (HD_NOTIFY FAR *) lParam;
Parameters
phdn
Pointer to an HD_NOTIFY structure that contains information about the header control and the item whose divider was double-clicked.
Return Values
No return value.
See Also