Swift

下面演示如何创建开关，以及监听它值的改变，代码如下：

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class ViewController: UIViewController {     var uiswitch:UISwitch!;     override func viewDidLoad() {             super.viewDidLoad()             uiswitch = UISwitch()             //设置位置（开关大小无法设置）             uiswitch.center=CGPointMake(100,50);             //设置默认值             uiswitch.on=true;             uiswitch.addTarget(self, action: Selector("switchDidChange"),             forControlEvents:UIControlEvents.ValueChanged)             self.view.addSubview(uiswitch);     }       func switchDidChange(){             //打印当前值             println(uiswitch.on)     } }