吸收效果，像是在Mac上的垃圾桶的效果一样

 1 #import "AppDelegate.h"
 2 #import <QuartzCore/QuartzCore.h>
 3 
 4 @interface AppDelegate ()
 5 @property (nonatomic ,strong)UIImageView *birdImage;
 6 @end
 7 
 8 @implementation AppDelegate
 9 
10 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
11     self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
12     // Override point for customization after application launch.
13     self.window.backgroundColor = [UIColor whiteColor];
14     // 创建UIImageView
15     self.birdImage = [[UIImageView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
16     //设置UIImageView可以操作
17     self.birdImage.userInteractionEnabled = YES;
18     // 添加图片
19     self.birdImage.image = [UIImage imageNamed:@"bird"];
20     // 轻拍手势
21     UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapAntion)];
22     // 给UIImageView添加手势
23     [self.birdImage addGestureRecognizer:tap];
24     [self.window addSubview:self.birdImage];
25  
26     [self.window makeKeyAndVisible];
27     return YES;
28 }
29 
30 - (void)tapAntion
31 {
32     // 设置层的背景颜色
33     self.window.layer.backgroundColor = [UIColor whiteColor].CGColor;
34     // 创建动画
35     CATransition *anim = [CATransition animation];
36     //设置代理
37     anim.delegate = self;
38     // 设置动画时间
39     anim.duration = 1.5;
40     //吸收效果，像是在Mac上的垃圾桶的效果一样（私有API，没有列入官方API）
41     anim.type = @"suckEffect";
42     [[self.birdImage layer] addAnimation:anim forKey:@"suckEffect"];
43     // 隐藏self.birdImage（若不隐藏，图片会保留在窗口）
44     self.birdImage.hidden = YES;
45 }
46 
47 @end