Header controls have a number of styles that determine the control's appearance and behavior. You set the initial styles when you create the header control. To retrieve and change the styles after creating the control, use the GetWindowLong and SetWindowLong functions.
A header control can be divided into two or more parts called header items. If a header control has the HDS_BUTTONS style, each item in the control looks and behaves like a push button. This style is useful if an application carries out a task when the user clicks an item in the header control. For example, an application could sort information in the columns differently depending on which item the user clicks.
The HDS_HORZ style creates a header control with a horizontal orientation.
The HDS_HIDDEN style indicates a header control that is intended to be hidden. This style does not hide the control. Instead, when you send the HDM_LAYOUT message to a header control with the HDS_HIDDEN style, the control returns zero in the cy member of the WINDOWPOS structure. You would then hide the control by setting its height to zero. This can be useful when you want to use the control as an information container and not as a visual control.