The index number identifying the selected segment (that is, the last segment touched).
- iOS 2.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
The default value is
UISegmented (no segment selected) until the user touches a segment. Set this property to -1 to turn off the current selection.
UISegmented ignores this property when the control is in momentary mode. When the user touches a segment to change the selection, the control event
UIControl is generated; if the segmented control is set up to respond to this control event, it sends a action message to its target.