iOS回弹动画效果

新建一个项目，然后在storyboard中放入一个View并用autolayout设置View的位置

和上边的距离（设置Y）

离左边的距离（设置X）

设置大小

给View拖一个输出口

在viewDidLoad中添加给view添加拖动手势

- (void)viewDidLoad {
    [super viewDidLoad];
    //添加拖动手势
    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] 	initWithTarget:self action:@selector(handlePan:)];
    [self.springbackView addGestureRecognizer:pan];
    // Do any additional setup after loading the view, typically from a nib.
}

接下来，实现handlePan:

- (void)handlePan:(UIPanGestureRecognizer*) recognizer{
    
    CGPoint translation = [recognizer translationInView:self.view];
    recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x,
                                         recognizer.view.center.y + translation.y);
    [recognizer setTranslation:CGPointZero inView:self.view];
    
    if (recognizer.state == UIGestureRecognizerStateEnded) {
    
        [UIView animateWithDuration:0.3 delay:0 usingSpringWithDamping:0.5 initialSpringVelocity:10 options:0 animations:^{
            [self.springbackView layoutIfNeeded];
    } completion:nil];
        
    }
}

OK,现在运行你的程序对View进行拖动吧。。。