This system-provided window procedure processes the actions on a scroll bar control (WC_SCROLLBAR).

Purpose

Scroll bars are controls used to indicate that additional information can be displayed in a window, logically to the left or right for horizontal scroll bars, logically above or below for vertical scroll bars. The user interface for scroll bars allows for scrolling one unit or one page at a time, or alternatively picking up the scroll bar slider and moving it to a position in the scroll bar that indicates a logical position in the data.

Scroll Bar Control Data

See SBCDATA for information on scroll bar control data.