BM_SETCHECK message

Sets the check state of a radio button or check box. You can send this message explicitly or by using the Button_SetCheck macro.

Parameters

wParam

The check state. This parameter can be one of the following values.

Value	Meaning
BST_CHECKED	Sets the button state to checked.
BST_INDETERMINATE	Sets the button state to grayed, indicating an indeterminate state. Use this value only if the button has the BS_3STATE or BS_AUTO3STATE style.
BST_UNCHECKED	Sets the button state to cleared.

lParam

This parameter is not used.

This message always returns zero.

The BM_SETCHECK message has no effect on push buttons.

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Header	Winuser.h (include Windows.h)