小知识六、CALayer动画

CAShapeLayer 圆形指示器

   let ovalShapeLayer: CAShapeLayer = CAShapeLayer()
   let anotherOvalShapeLayer: CAShapeLayer = CAShapeLayer()

   override func viewDidLoad() {
       super.viewDidLoad()
       loadingIndicator()
       beginSimpleAnimation()
       
       complexLoadingIndicator()
       complexAnimations()
   }
   
   // MARK: - 简单的加载指示器
   func loadingIndicator() {
       ovalShapeLayer.strokeColor = UIColor.white.cgColor
       ovalShapeLayer.fillColor = UIColor.clear.cgColor
       ovalShapeLayer.lineWidth = 7
       let ovalRadius = loadingView.bounds.size.height / 2.0 * 0.8
       ovalShapeLayer.path = UIBezierPath(ovalIn: CGRect(x: loadingView.frame.size.width/2 - ovalRadius, y: loadingView.frame.size.height/2 - ovalRadius, width: ovalRadius * 2, height: ovalRadius * 2)).cgPath
       ovalShapeLayer.strokeEnd = 0.4
       ovalShapeLayer.lineCap = kCALineCapRound
       loadingView.layer.addSublayer(ovalShapeLayer)
   }
   
   func beginSimpleAnimation() {
       let rotate = CABasicAnimation(keyPath: "transform.rotation")
       rotate.duration = 1.5
       rotate.fromValue = 0
       rotate.toValue = 2 * M_PI
       rotate.repeatCount = HUGE
       rotate.speed = 1
       loadingView.layer.add(rotate, forKey: nil)
       //loadingView.layer.anchorPoint = CGPoint(x: 0, y: 0)
   }
   
   // MARK: - 复杂的加载提示
   func complexLoadingIndicator() {
       anotherOvalShapeLayer.strokeColor = UIColor.white.cgColor
       anotherOvalShapeLayer.fillColor = UIColor.clear.cgColor
       anotherOvalShapeLayer.lineWidth = 3
       
       let anotherOvalRadius = complexLoadingView.frame.size.height/2 * 0.8
       anotherOvalShapeLayer.path = UIBezierPath(ovalIn: CGRect(x: complexLoadingView.frame.size.width/2 - anotherOvalRadius, y: complexLoadingView.frame.size.height/2 - anotherOvalRadius, width: anotherOvalRadius * 2, height: anotherOvalRadius * 2)).cgPath
       anotherOvalShapeLayer.lineCap = kCALineCapRound
       
       complexLoadingView.layer.addSublayer(anotherOvalShapeLayer)
   }
   
   func complexAnimations() {
       let strokeStartAnimate = CABasicAnimation(keyPath: "strokeStart")
       strokeStartAnimate.fromValue = -0.5
       strokeStartAnimate.toValue = 1
       
       let strokeEndAnimate = CABasicAnimation(keyPath: "strokeEnd")
       strokeEndAnimate.fromValue = 0.0
       strokeEndAnimate.toValue = 1
       
       let strokeAnimateGroup = CAAnimationGroup()
       strokeAnimateGroup.duration = 1.5
       strokeAnimateGroup.repeatCount = HUGE
       strokeAnimateGroup.animations = [strokeStartAnimate, strokeEndAnimate]
       anotherOvalShapeLayer.add(strokeAnimateGroup, forKey: nil)
   }

CAReplicatorLayer

/*CAReplicatorLayer是一个新面孔，它也是CALayer的子类，正如它的名称一样，CAReplicatorLayer可以对它自己的子Layer进行复制操作。
*/

    // MARK: - 正在播放音乐或广播动画
    func firstReplicatorAnimation() {
        
        let replicatorLayer = CAReplicatorLayer()
        replicatorLayer.bounds = CGRect(x: replicatorAnimationView.frame.origin.x, y: replicatorAnimationView.frame.origin.y, width: replicatorAnimationView.frame.size.width, height: replicatorAnimationView.frame.size.height)
        replicatorLayer.anchorPoint = CGPoint(x: 0, y: 0)
        replicatorLayer.backgroundColor = UIColor.clear.cgColor
        replicatorLayer.instanceCount = 3 // 设置三份
        replicatorLayer.instanceTransform = CATransform3DMakeTranslation(40, 0, 0) // 设置间隔
        replicatorLayer.instanceDelay = 0.3
        replicatorLayer.masksToBounds = true

        replicatorAnimationView.layer.addSublayer(replicatorLayer)
        
        
        let rectangle = CALayer()
        rectangle.bounds = CGRect(x: 0, y: 0, width: 30, height: 90)
        rectangle.anchorPoint = CGPoint(x: 0, y: 0)
        rectangle.position = CGPoint(x: replicatorAnimationView.frame.origin.x + 10, y: replicatorAnimationView.frame.origin.y + 110)
        rectangle.cornerRadius = 2
        rectangle.backgroundColor = UIColor.white.cgColor
        replicatorLayer.addSublayer(rectangle)
        
        let moveRectangle = CABasicAnimation(keyPath: "position.y")
        moveRectangle.toValue = rectangle.position.y - 70
        moveRectangle.duration = 0.7
        moveRectangle.autoreverses = true
        moveRectangle.repeatCount = HUGE
        rectangle.add(moveRectangle, forKey: nil)
    }
    
    func activityIndicatorAnimation() {
        
        let replicatorLayer = CAReplicatorLayer()
        replicatorLayer.bounds = CGRect(x: 0, y: 0, width: activityIndicatorView.frame.size.width, height: activityIndicatorView.frame.size.height)
        replicatorLayer.position = CGPoint(x: activityIndicatorView.frame.size.width/2, y: activityIndicatorView.frame.size.height/2)
        replicatorLayer.backgroundColor = UIColor.clear.cgColor
        
        
        replicatorLayer.instanceCount = 15
        let angle = CGFloat(2 * M_PI) / CGFloat(15)
        replicatorLayer.instanceTransform = CATransform3DMakeRotation(angle, 0, 0, 1)
        replicatorLayer.instanceDelay = 1/15
        activityIndicatorView.layer.addSublayer(replicatorLayer)
        
        
        let circle = CALayer()
        circle.bounds = CGRect(x: 0, y: 0, width: 15, height: 15)
        circle.position = CGPoint(x: activityIndicatorView.frame.size.width/2, y: activityIndicatorView.frame.size.height/2 - 55)
        circle.cornerRadius = 7.5
        circle.backgroundColor = UIColor.white.cgColor
        circle.transform = CATransform3DMakeScale(0.01, 0.01, 0.01)
        replicatorLayer.addSublayer(circle)
        
        
        let scale = CABasicAnimation(keyPath: "transform.scale")
        scale.fromValue = 1
        scale.toValue = 0.1
        scale.duration = 1
        scale.repeatCount = HUGE
        circle.add(scale, forKey: nil)
    }