HDM_INSERTITEM message

Inserts a new item into a header control. You can send this message explicitly or use the Header_InsertItem macro.

Parameters

wParam

The index of the item after which the new item is to be inserted. The new item is inserted at the end of the header control if wParam is greater than or equal to the number of items in the control. If wParam is zero, the new item is inserted at the beginning of the header control.

lParam

A pointer to an HDITEM structure that contains information about the new item.

Return value

Returns the index of the new item if successful, or -1 otherwise.

Requirements