(id)sender

//從UI中拉線所生成的方法中，sender永遠是主動呼叫這個方法的那個UI物件

- (IBAction)unitValueChanged:(id)sender

{

    UISegmentedControl *sc = (UISegmentedControl*)sender;

    _settingEntity.unit = [NSNumber numberWithInteger:sc.selectedSegmentIndex];

    [_settingEntity update];

}