弹出动画

//出现
- (void)showAnimal{
    self.transform = CGAffineTransformScale(CGAffineTransformIdentity, CGFLOAT_MIN, CGFLOAT_MIN);
    [UIView animateWithDuration:0.3 animations:^{
        // 以动画的形式将view慢慢放大至原始大小的1.2倍
        self.transform = CGAffineTransformScale(CGAffineTransformIdentity, 1.2, 1.2);
    } completion:^(BOOL finished) {
        [UIView animateWithDuration:0.2 animations:^{
            // 以动画的形式将view恢复至原始大小
            self.transform = CGAffineTransformIdentity;
        }];
    }];
}
//隐藏
- (void)hiddenView{
    [UIView animateWithDuration:0.2 animations:^{
        self.transform = CGAffineTransformScale(CGAffineTransformIdentity, 1.2, 1.2);
    } completion:^(BOOL finished) {
        [UIView animateWithDuration:0.3 animations:^{
            self.transform = CGAffineTransformScale(CGAffineTransformIdentity, 0.001, 0.001);
        } completion:^(BOOL finished) {
            [self removeFromSuperview];
        }];
    }];
}