我已将此动画写入 CAShapeLayer (pulseLayer) 并在viewDidLoad()
:
let pulseLayer = CAShapeLayer()
@IBOutlet weak var btnCart: UIButton!
override func viewDidLoad() {
let longpress = UILongPressGestureRecognizer(target: self, action: #selector(CategoryViewController.longPressGestureRecognized(_:)))
tableView.addGestureRecognizer(longpress)
heartBeatAnimation.duration = 0.75
heartBeatAnimation.repeatCount = Float.infinity
heartBeatAnimation.autoreverses = true
heartBeatAnimation.fromValue = 1.0
heartBeatAnimation.toValue = 1.2
heartBeatAnimation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseIn)
btnCart.layer.addSublayer(pulseLayer)
}
func addBtnCartLayerWithAnimation() {
let ovalPath = UIBezierPath(arcCenter: CGPoint(x: btnCart.frame.midX, y: btnCart.frame.midY), radius: btnCart.frame.width * 1.5, startAngle: 0*(CGFloat.pi / 180), endAngle: 360*(CGFloat.pi / 180), clockwise: true)
pulseLayer.path = ovalPath.cgPath
pulseLayer.opacity = 0.15
pulseLayer.anchorPoint = CGPoint(x: 0.5, y: 0.5)
pulseLayer.bounds = ovalPath.cgPath.boundingBox
pulseLayer.add(heartBeatAnimation, forKey: "heartBeatAnimation")
pulseLayer.transform = CATransform3DScale(CATransform3DIdentity, 1.0, 1.0, 1.0)
}
removeLayer 函数是:
func removeLayer() {
pulseLayer.transform = CATransform3DScale(CATransform3DIdentity, 0.1, 0.1, 0.1)
pulseLayer.removeAllAnimations()
}
问题是当图层的第一个动画来自视图的底部时!
然后从中心(定义的锚点)开始对此动画的任何调用
谁能告诉我为什么会这样?
我在 tableView 上定义和使用的整个类UILongGestureRecognizer
来启动/停止动画:
func longPressGestureRecognized(_ gestureRecognizer: UIGestureRecognizer) {
let longPress = gestureRecognizer as! UILongPressGestureRecognizer
let state = longPress.state
let locationInView = longPress.location(in: tableView)
let indexPath = tableView.indexPathForRow(at: locationInView)
switch state {
case UIGestureRecognizerState.began:
if indexPath != nil {
addBtnCartLayerWithAnimation()
}
case UIGestureRecognizerState.changed:
// some code here not related to the animation
default:
removeLayer()
}
}