import UIKit

class ViewController: UIViewController {

    var uiswitch: UISwitch?

    override func viewDidLoad() {

        super.viewDidLoad()

        uiswitch = UISwitch()

        // 设置位置 (开关无法设置大小)

        uiswitch?.center = CGPoint(x: 100, y: 50)

        self.view.addSubview(uiswitch!)

        // 设置默认值

        uiswitch?.isOn = true

        uiswitch?.addTarget(self, action: #selector(switchDidChange), for: .valueChanged)

    }

    func switchDidChange(){

        // 打印当前值

        print(uiswitch!.isOn)

    }

    override func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

        // Dispose of any resources that can be recreated.

    }

}