伸缩式动画

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    self.title=@"伸缩式动画";
}
//点击任何处，弹出动画
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    
    UIView *zanView = [[UIView alloc] initWithFrame:CGRectMake(50, 100, 100, 100)];
    zanView.backgroundColor = [UIColor redColor];
    [self.view addSubview:zanView];
    
    [UIView animateWithDuration:0.3 animations:^{
        zanView.transform = CGAffineTransformMakeScale(1.2, 1.2);
    } completion:^(BOOL finished) {
        [UIView animateWithDuration:0.3 animations:^{
            zanView.transform = CGAffineTransformMakeScale(0.9, 0.9);
        } completion:^(BOOL finished) {
            [UIView animateWithDuration:0.3 animations:^{
                zanView.transform = CGAffineTransformMakeScale(1.0, 1.0);
            } completion:^(BOOL finished) {
                
            }];
        }];
    }];
    
}