如何快速找到 UIButton 的正确位置？

Question

嗨，我尝试快速对按钮应用脉冲效果。

但是每次我应用它时，按钮上方总是有一个脉冲效果。

@IBAction func btnAction(_ sender: UIButton) {
    var position = sender.center

    let pulse = PulseAnimation(numberOfPulses: Float.infinity, radius: 100, position: position) }

如何找到 UIButton 的 Real CGPoint？ 谢谢。

PulseAnimation.swift

class PulseAnimation: CALayer {

var animationGroup = CAAnimationGroup()
var animationDuration: TimeInterval = 1.5
var radius: CGFloat = 200
var numberOfPulses: Float = 10

override init(layer: Any) {
    super.init(layer: layer)
}

required init?(coder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}

init(numberOfPulses: Float = 10, radius: CGFloat, position: CGPoint) {
    super.init()
    self.backgroundColor = UIColor.black.cgColor
    self.contentsScale = UIScreen.main.scale
    self.opacity = 0
    self.radius = radius
    self.numberOfPulses = numberOfPulses
    self.position = position

    self.bounds = CGRect(x: 0, y: 0, width: radius*2, height: radius*2)
    self.cornerRadius = radius

    DispatchQueue.global(qos: DispatchQoS.QoSClass.default).async {
        self.setupAnimationGroup()
        DispatchQueue.main.async {
            self.add(self.animationGroup, forKey: "pulse")
        }
    }
}

func scaleAnimation() -> CABasicAnimation {
    let scaleAnimation = CABasicAnimation(keyPath: "transform.scale.xy")
    scaleAnimation.fromValue = NSNumber(value: 0)
    scaleAnimation.toValue = NSNumber(value: 1)
    scaleAnimation.duration = animationDuration
    return scaleAnimation
}

func createOpacityAnimation() -> CAKeyframeAnimation {
    let opacityAnimation = CAKeyframeAnimation(keyPath: "opacity")
    opacityAnimation.duration = animationDuration
    opacityAnimation.keyTimes = [0, 0.3, 1]
    opacityAnimation.values = [0.4, 0.8, 0]
    return opacityAnimation
}
func setupAnimationGroup() {
    self.animationGroup.duration = animationDuration
    self.animationGroup.repeatCount = numberOfPulses
    let defaultCurve = CAMediaTimingFunction(name: .default)
    self.animationGroup.timingFunction = defaultCurve
    self.animationGroup.animations = [scaleAnimation(), createOpacityAnimation()]
}
}

它是一个应用脉冲效果的类。 它使用 CGPoint 为其设置动画，并仅使用位置到 self.position。 不知道为什么位置不对。 谢谢解答。

Answer 1

真正的 CGPoint 你想知道的是一个 CGPoint 有 x 范围 0~sender.frame.width 和 y 范围 0~sender.height 试试这个。 :)

    @IBAction func buttonAction(_ sender: UIButton) {
        let position = CGPoint(x: sender.frame.width * 0.5, y: sender.frame.height * 0.5)

        let pulse = PulseAnimation(numberOfPulses: Float.infinity, radius: 100, position: position)
        sender.layer.addSublayer(pulse)

    }

Answer 2

我不知道 PulseAnimation 类是做什么的，但是通过搜索，我可以找到有关它的主题并将其应用于我的代码以测试预期效果。

  @IBAction func numberHit(_ sender: UIButton) {
        let pulseAnimation = CABasicAnimation(keyPath: "opacity")
        pulseAnimation.duration = 30
        pulseAnimation.fromValue = 0
        pulseAnimation.toValue = 1
        pulseAnimation.timingFunction = CAMediaTimingFunction(name: .easeInEaseOut)
        pulseAnimation.autoreverses = true
        pulseAnimation.repeatCount = .greatestFiniteMagnitude
        sender.layer.add(pulseAnimation, forKey: nil)
}

请查看： Swift Pulse Animation