我希望能够制作一个小红点绕着一个脉冲扩大的圆旋转(从小到大再回到小),但似乎小红点始终绕着原始形状旋转,并没有考虑到正在扩大的圆形... 我在代码中有以下内容:
// MARK: - Properties
private lazy var containerView = UIView()
let littleCircleRadius: CGFloat = 10
private lazy var littleRedDot: CALayer = {
let layer = CALayer()
layer.backgroundColor = UIColor.red.cgColor
let littleDotSize = CGSize(width: 10, height: 10)
layer.frame = CGRect(x: containerView.bounds.center.x - littleDotSize.width / 2,
y: containerView.bounds.center.y - littleCircleRadius - littleDotSize.width/2 ,
width: littleDotSize.width,
height: littleDotSize.height)
return layer
}()
private lazy var littleCircleLayer: CAShapeLayer = {
let layer = CAShapeLayer()
layer.lineWidth = 1.5
layer.lineCap = .round
layer.strokeColor = UIColor.black.cgColor
layer.fillColor = UIColor.clear.cgColor
return layer
}()
// MARK: - Setup
func setup() {
view.addSubview(containerView)
containerView.frame = CGRect(x: 40, y: 200, width: 300, height: 300)
containerView.backgroundColor = UIColor.gray.withAlphaComponent(0.2)
littleCircleLayer.path = makeArcPath(arcCenter: containerView.bounds.center, radius: 10)
containerView.layer.addSublayer(littleCircleLayer)
containerView.layer.addSublayer(littleRedDot)
}
// MARK: - Animations
func animate() {
CATransaction.begin()
CATransaction.setAnimationDuration(1.5)
animateLittleRedDotRotation()
animateCircleExpanding()
CATransaction.commit()
}
func animateLittleRedDotRotation() {
let anim = CAKeyframeAnimation(keyPath: "position")
anim.duration = 1.5
anim.rotationMode = .rotateAuto
anim.repeatCount = Float.infinity
anim.path = littleCircleLayer.path
littleRedDot.add(anim, forKey: "rotate")
}
func animateCircleExpanding() {
let maxCircle = makeArcPath(arcCenter: containerView.bounds.center, radius: 100)
let circleExpandingAnim = CABasicAnimation(keyPath: "path")
circleExpandingAnim.fromValue = littleCircleLayer.path
circleExpandingAnim.toValue = maxCircle
circleExpandingAnim.repeatCount = Float.infinity
circleExpandingAnim.duration = 1.5
littleCircleLayer.add(circleExpandingAnim, forKey: "pulseCircuitAnimation")
}
这会产生以下效果: 但是我想让小点沿着扩张圆形路径旋转(当它从小圆变为大圆时),而不是原始的小圆路径。有什么意见吗?