iOS动画（二）CoreAnimation

1、CoreAnimation的结构如下

1.png

2、CoreAnimation类介绍

(1)CAAnimation ---> CoreAnimation的基础类

两个代理方法，监听动画的开始和结束

• (void)animationDidStart:(CAAnimation *)anim;

• (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag;

(2)CABasicAnimation ---> 基本动画

@property(nullable, strong) id fromValue;
@property(nullable, strong) id toValue;
@property(nullable, strong) id byValue;

①实现大小、角度、位置的变化通过transform来实现:

CATransform3D transform = CATransform3D ＋ （Make）＋ Translate、Scale、Rotation
animation.toValue = [NSValue valueWithCATransform3D:transform];

//旋转
- (void)rotation
{
  //实现180度的无限旋转
    CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"transform"];
    anim.duration = 1;
    anim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
    anim.byValue = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(M_PI_2, 0, 0, 1)];
    anim.removedOnCompletion = NO;
    anim.fillMode = kCAFillModeForwards;
    [self.myView.layer addAnimation:anim forKey:nil];
}

//位置
- (void)positon
{
  //实现位置的移动
    CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"transform"];
    CATransform3D form = CATransform3DMakeTranslation(350, 350, 0);
    anim.toValue = [NSValue valueWithCATransform3D:form];
    anim.duration = 1;
    anim.removedOnCompletion = NO;
    anim.fillMode = kCAFillModeForwards;
    [self.myView.layer addAnimation:anim forKey:nil];
}

//大小
- (void)scale
{
  //实现大小的变化
    CABasicAnimation *anim = [CABasicAnimation animation];
    anim.keyPath = @"transform";
    CATransform3D form = CATransform3DMakeScale(1.2, 1.2, 1);
    anim.toValue =  [NSValue valueWithCATransform3D:form];
    anim.duration = 0.5;
    anim.repeatCount = MAXFLOAT;
    anim.autoreverses = YES;
    [self.myView.layer addAnimation:anim forKey:nil];
}

②实现大小、位置的变化通过bounds、position来实现:

//大小
- (void)scale
{
    CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"bounds"];
    anim.duration = 2;
    anim.toValue = [NSValue valueWithCGRect:CGRectMake(0, 0, 30, 30)];
    [_myView.layer addAnimation:anim forKey:nil];
    
}

//位置
- (void)positon
{
    CABasicAnimation *anim = [CABasicAnimation animation];
    anim.keyPath = @"position";
    anim.toValue = [NSValue valueWithCGPoint:CGPointMake(250, 500)];
    
    // 取消反弹
    anim.removedOnCompletion = NO;
    anim.fillMode = kCAFillModeForwards;
    
    [_myView.layer addAnimation:anim forKey:nil];
}

（3）CAKeyframeAnimation --->关键帧动画

@property(nullable, copy) NSArray *values;
@property(nullable, copy) NSArray<NSNumber *> *keyTimes;
@property(nullable) CGPathRef path;

//位置1
- (void)position1
{
  //多步动画
    CAKeyframeAnimation *animation = [CAKeyframeAnimation animation];
    animation.keyPath = @"position.x";
    animation.values = @[ @0, @10, @-10, @10, @0 ];
    //设置每一帧执行的时间长短 这个的取值为0-1，代表占用时间的比例
    animation.keyTimes = @[ @0, @(1 / 6.0), @(3 / 6.0), @(5 / 6.0), @1 ];
    animation.duration = 0.4;
    //设置帧的中间值如何计算
    animation.calculationMode = kCAAnimationPaced;
    //这个属性确定动画执行的状态是否叠加在控件的原状态上
    //默认设置为NO，如果我们执行两次位置移动的动画，会从同一位置执行两次
    //如果设置为YES，则会在第一次执行的基础上执行第二次动画
    animation.additive = YES;
    //如果设置为YES,代表动画每次重复执行的效果会跟上一次相反
    animation.autoreverses = YES;
    [self.myView.layer addAnimation:animation forKey:@"position1"];
    self.myView.layer.zPosition = 1;

}

//位置2
- (void)position2
{
    //沿贝塞尔曲线的动画

    // 这个方法将创建椭圆形路径
    CGRect boundingRect = CGRectMake(0, 0, 300, 300);
    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:boundingRect cornerRadius:150];

    CAKeyframeAnimation *animation = [CAKeyframeAnimation animation];
    animation.keyPath = @"position";
    //设置一个路径    
    animation.path = path.CGPath;
  
    animation.duration = 4;
    animation.additive = YES;
    animation.repeatCount = HUGE_VALF;
    animation.calculationMode = kCAAnimationPaced;
    animation.rotationMode = kCAAnimationRotateAuto;
    [self.myView.layer addAnimation:animation forKey:nil];
}

（4）CASpringAnimation ---> 弹性动画

-(void)springAnimation{

    CASpringAnimation *animation = [CASpringAnimation animationWithKeyPath:@"position"];
    animation.toValue = [NSValue valueWithCGPoint:CGPointMake(175, 400)];

    //质量，影响图层运动时的弹簧惯性，质量越大，弹簧拉伸和压缩的幅度越大
    //如果把质量改成10，则动画变成 动画的速度变慢，并且波动幅度变大
    animation.mass = 1;
    //阻尼系数，阻止弹簧伸缩的系数，阻尼系数越大，停止越快
    animation.damping = 30;
    //初始速率 动画视图的初始速度大小
    animation.initialVelocity = 10;
    //刚度 刚度系数越大，形变产生的力就越大，运动越快
    animation.stiffness = 10;

    animation.duration = animation.settlingDuration;
    animation.fillMode = kCAFillModeForwards;
    animation.removedOnCompletion = NO;
    [self.myView.layer addAnimation:animation forKey:@"springAnimation"];
}

（5）CATransition ---> 转场动画

@property(copy) NSString *type; 动画过渡类型 ----->fade',moveIn', push' andreveal'. Defaults to fade'. @property(nullable, copy) NSString *subtype; 动画过渡方向 ----->fromLeft', fromRight',fromTop' and * `fromBottom'

23.png

- (void)transition
{
    CATransition * ani = [CATransition animation];
    ani.type =  @"pageCurl";
    ani.subtype = kCATransitionFromRight;
    [self.myView.layer addAnimation:ani forKey:@""];
}

（5）CAAnimationGroup ---> 动画组

@property(nullable, copy) NSArray<CAAnimation *> *animations;

3、动画暂停和重启

//暂停
-(void)pauseAnimation
{
    CFTimeInterval pausedTime = [self.myView.layer convertTime:CACurrentMediaTime() fromLayer:nil];
    
    // 让CALayer的时间停止走动
    self.myView.layer.speed = 0.0;
    // 让CALayer的时间停留在pausedTime这个时刻
    self.myView.layer.timeOffset = pausedTime;
}

//重启
-(void)resumeAnimation
{
    CFTimeInterval pausedTime = self.myView.layer.timeOffset;
    // 1. 让CALayer的时间继续行走
    self.myView.layer.speed = 1.0;
    // 2. 取消上次记录的停留时刻
    self.myView.layer.timeOffset = 0.0;
    // 3. 取消上次设置的时间
    self.myView.layer.beginTime = 0.0;
    // 4. 计算暂停的时间(这里也可以用CACurrentMediaTime()-pausedTime)
    CFTimeInterval timeSincePause = [self.myView.layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
    // 5. 设置相对于父坐标系的开始时间(往后退timeSincePause)
    self.myView.layer.beginTime = timeSincePause;
}