iOS动画系列之六：利用CABasic Animation完成带动画特效的登录界面1. 画风突变的笑脸2. 心跳3. iOS实践：实现一个带动效的登录界面

- (void)viewDidLoad {
    [super viewDidLoad];
    
    //设置头部标题的文字
    self.titleLabel.text = @"吓死宝宝了！";
    
    //暂时先隐藏头部标题，等动画播放完成再显示
    [self.titleLabel setHidden:YES];
}

//    触摸屏之后触发的方法
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    
    __weak typeof(self) weakSelf = self;
     
    //添加阻尼动画
    [UIView animateWithDuration:0.8 delay:0.2 usingSpringWithDamping:0.6 initialSpringVelocity:0.8 options:UIViewAnimationOptionTransitionNone animations:^{

        //改变黄色的中心点位置
        weakSelf.yellowView.center = CGPointMake(weakSelf.view.bounds.size.width - weakSelf.yellowView.center.x, weakSelf.yellowView.center.y + 30);
                
        //改变蓝色的中心点位置
        weakSelf.greenView.center = CGPointMake(weakSelf.view.bounds.size.width - weakSelf.greenView.center.x, weakSelf.greenView.center.y + 30);
        
        //改变嘴巴的高度和中心点y的位置
        CGRect frame = CGRectMake(weakSelf.mouseView.frame.origin.x, weakSelf.mouseView.frame.origin.y, weakSelf.mouseView.frame.size.width, 180);
        
        weakSelf.mouseView.frame = frame;
        
        //这句一定要加，不然看不到动画
        [weakSelf.view layoutIfNeeded];
    } completion:^(BOOL finished) {
               
        //添加阻尼动画     
        [UIView animateWithDuration:0.2 delay:0 usingSpringWithDamping:0.6 initialSpringVelocity:0.8 options:UIViewAnimationOptionTransitionNone animations:^{
            //把隐藏的标题文字设置为显示状态
            [weakSelf.titleLabel setHidden:NO];
        } completion:nil];
    }];
    
}

+(void)animateWithDuration:(NSTimeInterval)**duration** delay:(NSTimeInterval)**delay** usingSpringWithDamping:(CGFloat)**dampingRatio** initialSpringVelocity:(CGFloat)**velocity** options:(UIViewAnimationOptions)**options** animations:(void (^)(void))**animations** completion:(void (^__nullable)(BOOL finished))**completion**;

__weak typeof(self) weakSelf = self;

    //        将❤️图层绘制上图片
    heartLayer.contents = (__bridge id _Nullable)([heartImage CGImage]);

    //        设置照片消失的动画
    [UIView animateWithDuration:2.0 animations:^{
        photoImageView.alpha = 0;
    }];

    //        动画的节奏。心跳的节奏。为了让更有节奏感一些，使用了快进快出模式。
    scaleAni.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

//        将导航栏隐藏
[self.navigationController setNavigationBarHidden:YES];

//    设置电池栏的状态为白色
- (UIStatusBarStyle)preferredStatusBarStyle{
return UIStatusBarStyleLightContent;
}

//        设置登录和注册两个btn的圆角
self.signBtn.layer.cornerRadius = 5;
self.loginBtn.layer.cornerRadius = 5;

//在动画没有播放完成之前，关闭按钮的交互
[weakSelf.loginBtn setEnabled:NO];