This system-provided window procedure processes the actions on a spin button control (WC_SPINBUTTON).

Purpose

A spin button control (WC_SPINBUTTON window class) is a visual component whose specific purpose is to give users quick access to a finite set of data. The spin button allows users to select from a scrollable ring of choices. Since users can see only one item at a time, the spin button control should be used only with data that is intuitively related, such as a list of months of the year, or an alphabetic list of cities or states.

A spin button consists of at least one spin field that is a single-line entry field (SLE), and up and down arrows that are stacked on top of one another. These arrows are positioned at the right of the SLE.

You can create multifield spin buttons for those applications in which users must select more than one value. For example, in setting a date the spin button control can provide individual fields for setting the month, day, and year. The first spin field in the spin button could contain a list of months, the second spin field could contain a list of numbers and the third spin field could contain a list of years.