BM QUERYCHECKINDEX

This message returns the zero-based index of a checked radio button.

Syntax

param1
    ULONG ulReserved; /* Reserved value, should be 0. */

param2
    ULONG ulReserved; /* Reserved value, should be 0. */

Parameters

ulReserved (ULONG) - input: Reserved value, should be 0.
ulReserved (ULONG) - input: Reserved value, should be 0.

Returns

sIndex (SHORT) - returns

Radio-button index.

-1: No radio button of the group is checked, or this button control does not have the style BS_RADIOBUTTON or BS_AUTORADIOBUTTON.

Other: Zero-based index of the checked radio button of the group.

Remarks

The button control responds to this message by setting sIndex as appropriate.

This message may be sent to any radio button or autoradio button in a group of buttons. For details of the WS_GROUP style, see Window Styles.

Default Processing

The default window procedure does not expect to receive this message and therefore takes no action on it, other than to set sIndex to the default value of 0.