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

For information on button control data see BTNCDATA.

Purpose

A button control is a small rectangular child window representing a button that the operator can "switch" on or off. Button controls can be used alone or in groups, and can either be labeled or appear without text. Button controls typically change appearance when the operator clicks a pointing device on them or pressing the space bar when the button has the keyboard focus.

Buttons can be disabled to prevent them from responding when the operator clicks on them. Disabled buttons are displayed using a different emphasis technique (for example, color or half-toning).