CAReplicatorLayer(重复图层)

CAReplicatorLayer的目的是为了高效生成许多相似的图层。它会绘制一个或多个图层的子图层，并在每个复制体上应用不同的变换。

gitHub地址在/layer/replicatorLayer里面

CAReplicatorLayer属性说明：

• @property NSInteger instanceCount;
  指定图层需要重复多少次

• @property CFTimeInterval instanceDelay;
  图层出现的延迟

• @property CATransform3D instanceTransform;
  重复图层的transform

• @property(nullable) CGColorRef instanceColor;
  重复图层的颜色

• @property float instanceRedOffset;
  @property float instanceGreenOffset;
  @property float instanceBlueOffset;
  @property float instanceAlphaOffset;
  重复图层的颜色渐变值

1、圆形重复图层效果

达到的效果为：

replicatorLayer-1

示例代码为：

/**
 * @func 重复图层圆形
 */
-(void)cicleReplicatorLayer{
    //创建一个ReplicatorLayer
    CAReplicatorLayer * replicatorLayer = [CAReplicatorLayer layer];
    //设置大小
    replicatorLayer.frame = self.bounds;
    [self.layer addSublayer:replicatorLayer];
    
    //设置ReplicatorLayer的复制个数
    replicatorLayer.instanceCount = 10;
    //给每个instance添加transform
    CATransform3D transform = CATransform3DIdentity;
    //向下平移200
//    transform = CATransform3DTranslate(transform, 50, 0, 0);
    //绕着Z轴旋转
    transform = CATransform3DRotate(transform, M_PI/5.0, 0, 0, 1);
    //上移200
    transform = CATransform3DTranslate(transform, -50, 50, 0);
    replicatorLayer.instanceTransform = transform;
    //添加渐变颜色
    replicatorLayer.instanceBlueOffset = -0.1;
    replicatorLayer.instanceGreenOffset = -0.1;
    //设置subLayer和位置大小
    CALayer * layer = [CALayer layer];
    layer.frame = CGRectMake(50, 100, 50, 50);
    layer.backgroundColor = [UIColor whiteColor].CGColor;
    [replicatorLayer addSublayer:layer];
}

2、实现一个雷达的动画

实现效果为：

雷达效果.gif

示例代码：

/**
 *雷达动画
 */
-(void)radarAnimation{
//    创建一个shaperLayer图层，也就是做变大动画
    CAShapeLayer * shaperLayer = [CAShapeLayer layer];
    shaperLayer.backgroundColor = [UIColor whiteColor].CGColor;
    shaperLayer.bounds = CGRectMake(0, 0, 20, 20);
    shaperLayer.cornerRadius = 10;
    shaperLayer.position = CGPointMake(kWidth/2, kHeight/2);
//    创建动画
    CABasicAnimation *transform = [CABasicAnimation animationWithKeyPath:@"transform"];
    NSValue *value = [NSValue valueWithCATransform3D:CATransform3DMakeScale(10, 10, 1)];
    transform.toValue = value;
    transform.duration = 3;
    transform.repeatCount = MAXFLOAT;
    //设置透明度，可以直接设置replicatorLayer的instanceAlphaOffset来设置
    CABasicAnimation * alpha = [CABasicAnimation animationWithKeyPath:@"opacity"];
    alpha.fromValue = @(1);
    alpha.toValue = @(0);
    alpha.duration = 2;
//    创建动画组
    CAAnimationGroup * group = [CAAnimationGroup animation];
    group.animations = @[transform,alpha];
    group.duration = 2;
    group.repeatCount = MAXFLOAT;
    [shaperLayer addAnimation:group forKey:@"radarAnimation"];
//    创建replicatorLayer
    CAReplicatorLayer * replicatorLayer = [CAReplicatorLayer layer];
    [replicatorLayer addSublayer:shaperLayer];
//    复制层的个数
    replicatorLayer.instanceCount = 3;
//    复制层延迟时间
    replicatorLayer.instanceDelay = 0.5;
//    replicatorLayer.instanceAlphaOffset = -0.1;
    [self.layer addSublayer:replicatorLayer];
}

3、圆点缩放转圈效果

实现效果为：

圆点缩放转圈.gif

示例代码：

/**
 * @func 转圈动画，带大小缩放
 */
-(void)cicleScaleAnimation{
    //创建一个shaperLayer,动画效果layer
    CAShapeLayer * shaperLayer = [CAShapeLayer layer];
    shaperLayer.backgroundColor = [UIColor whiteColor].CGColor;
    shaperLayer.bounds = CGRectMake(0, 0, 20, 20);
    shaperLayer.cornerRadius = 10;
    shaperLayer.position = CGPointMake(kWidth/2, 100);
    shaperLayer.transform = CATransform3DMakeScale(0.1, 0.1, 0.1);
    
    //创建缩放动画
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform"];
    animation.duration = 2;
    animation.repeatCount = MAXFLOAT;
    //动画起始为原来大小
    animation.fromValue = [NSValue valueWithCATransform3D:CATransform3DMakeScale(1, 1, 1)];
    //动画结束为原来的0.1倍
    animation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeScale(0.1, 0.1, 0.1)];
    [shaperLayer addAnimation:animation forKey:nil];
    
    //创建replicatorLayer
    CAReplicatorLayer * replicatorLayer = [CAReplicatorLayer layer];
    //这里设置的高度500，显示区域Y值在100-（500-100）之间，动画占用区域高度为300
    replicatorLayer.frame = CGRectMake(0, 0, kWidth, 500);
    [replicatorLayer addSublayer:shaperLayer];
//重复层的个数
    replicatorLayer.instanceCount = 20;
//重复层的延时
    replicatorLayer.instanceDelay = 0.1;
    CGFloat angle = 2*M_PI / 20.0;
    //创建replicatorLayer的instance的transform绕着Z轴旋转angle角度
    replicatorLayer.instanceTransform = CATransform3DMakeRotation(angle, 0, 0, 1);
    [self.layer addSublayer:replicatorLayer];
}

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这是重复图层的用法，其他效果，大家可以自己尝试。