Xcode9学习笔记79

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        //主线程休眠2秒，启动画面将停留2秒
        Thread.sleep(forTimeInterval: 2)
        
        let view = UIView(frame: CGRect(x: 40, y: 80,  240, height: 100))
        view.backgroundColor = UIColor.brown
        self.view.addSubview(view)
    }