The HDM_INSERTITEM message inserts a new item into a header control. You can send this message explicitly or by using the Header_InsertItem macro.
HDM_INSERTITEM
wParam = (WPARAM) (int) index;
lParam = (LPARAM) (const HD_ITEM FAR*) phdi;
Parameters
index
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 index is greater than or equal to the number of items in the control. If index is zero, the new item is inserted at the beginning of the header control.
phdi
Pointer to an HD_ITEM structure that contains information about the new item.
Return Values
If the operation succeeds, the return value is the index of the new item.
If the operation fails, the return value is - 1.
See Also