Xcode9学习笔记59

    override func viewDidLoad() {        super.viewDidLoad()        // Do any additional setup after loading the view, typically from a nib.        let rect = CGRect(x: 58, y: 40, width: 200, height: 200)        let imageView = UIImageView(frame: rect)        let image = UIImage(named: "Pic")        imageView.image = image//给图像视图添加要显示的图片        imageView.tag = 1//设置图像视图的标识值，以方便后期对图像视图的调用                self.view.addSubview(imageView)                let button = UIButton(type: UIButtonType.system)//初始化一个按钮对象，点击按钮时播放动画        button.frame = CGRect(x: 58, y: 400, width: 200, height: 44)        button.backgroundColor = UIColor.lightGray        button.setTitle("Tap", for: UIControlState())        button.addTarget(self, action: #selector(ViewController.playAnimation), for: UIControlEvents.touchUpInside)                self.view.addSubview(button)    }        @objc func playAnimation() {        UIView.beginAnimations(nil, context: nil)//发出开始动画的请求        UIView.setAnimationCurve(.easeOut)//设置动画的播放速度为淡入淡出        UIView.setAnimationDuration(5)//设置动画时长5秒        UIView.setAnimationBeginsFromCurrentState(true)//设置动画从当前状态开始播放        let view = self.view.viewWithTag(1)//通过标识值找到之前创建的图像视图，作为动画的载体        UIView.setAnimationTransition(.flipFromRight, for: view!, cache: true)//设置动画类型为翻转动画        UIView.commitAnimations()//调用视图的提交动画方法，标志着动画块的结束    }