ios - 如何快速找到 UIButton 的正确位置?
问题描述
嗨,我尝试快速对按钮应用脉冲效果。
但每次我应用它时,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 对其进行动画处理,并且只使用位置到 self.position。我不知道为什么位置不正确。感谢回答。
解决方案
真正的 CGPoint 你想知道的是一个 CGPoint,它有 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)
}