This message checks or removes the checkmark from a radio button or check box.
| Parameter | Description |
| wParam | Specifies whether to place or remove a checkmark inside the button or box. If the wParam parameter is nonzero, a checkmark is placed; if it is zero, the checkmark (if any) is removed. For three-state buttons, if wParam is 1, a checkmark is placed beside the button. If wParam is 2, the button is grayed. If wParam is zero, the button is returned to its normal state (no checkmark or graying). | |
| lParam | Is not used. |
The BM_SETCHECK message has no effect on push buttons.