汤姆猫的小游戏，当我触发某个指令时，比如喝牛奶、吃东西等，会产生一个动画。今天我们来学习如何用帧动画来实现。

帧动画我们应该知道，这是播放动画的一般方法，通过在短时间内播放一组连续的图片来达到动画效果。

下面实例中只演示喝牛奶、吃东西这俩个动画，其他动画原理一样：

import UIKit

class ViewController: UIViewController {
    //用于播放的UIImageView
    @IBOutlet weak var catIv: UIImageView!;
    
    //喝牛奶
    @IBAction func drink() {
        //1.加载图片到数组中
        var imgArray = [UIImage]();
        for var i = 0; i<81; ++i{
            var imgName = i<10 ? "drink_0\(i)" : "drink_\(i)";
            var image:UIImage = UIImage(named: imgName)!;
            imgArray.insert(image,atIndex: i);
        }
        //2.将数组添加到UIImageView中
        self.catIv.animationImages = imgArray;
        //3.设置动画持续时间
        self.catIv.animationDuration = Double(imgArray.count) * 0.1;
        //4.设置动画持续次数
        self.catIv.animationRepeatCount = 1;
        //5.开启动画
        self.catIv.startAnimating();

    }
    //吃东西
    @IBAction func eat() {
        //1.加载图片到数组中
        var imgArray = [UIImage]();
        for var i = 0; i<40; ++i{
            var imgName = i<10 ? "eat_0\(i)" : "eat_\(i)";
            var image:UIImage = UIImage(named: imgName)!;
            imgArray.insert(image,atIndex: i);
        }
        //2.将数组添加到UIImageView中
        self.catIv.animationImages = imgArray;
        //3.设置动画持续时间
        self.catIv.animationDuration = Double(imgArray.count) * 0.1;
        //4.设置动画持续次数
        self.catIv.animationRepeatCount = 1;
        //5.开启动画
        self.catIv.startAnimating();
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view,typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}