swift:创建眩光按钮动画

import UIKit

class GlowingButton: UIButton {
    override var isHighlighted: Bool {
        didSet {
            if isHighlighted {
                // 创建一个光晕效果的CALayer
                let glowLayer = CALayer()
                glowLayer.bounds = bounds
                glowLayer.position = CGPoint(x: bounds.midX, y: bounds.midY)
                glowLayer.cornerRadius = bounds.height / 2
                glowLayer.backgroundColor = UIColor.yellow.cgColor
                
                // 创建一个缩放动画
                let scaleAnimation = CABasicAnimation(keyPath: "transform.scale")
                scaleAnimation.fromValue = 1.0
                scaleAnimation.toValue = 1.2
                scaleAnimation.duration = 0.2
                scaleAnimation.autoreverses = true
                
                // 创建一个透明度动画
                let opacityAnimation = CABasicAnimation(keyPath: "opacity")
                opacityAnimation.fromValue = 0.0
                opacityAnimation.toValue = 0.8
                opacityAnimation.duration = 0.2
                opacityAnimation.autoreverses = true
                
                // 创建一个动画组合
                let animationGroup = CAAnimationGroup()
                animationGroup.animations = [scaleAnimation, opacityAnimation]
                animationGroup.duration = 0.4
                animationGroup.timingFunction = CAMediaTimingFunction(name: .easeInEaseOut)
                
                // 将动画添加到光晕层上
                glowLayer.add(animationGroup, forKey: "glowAnimation")
                
                // 将光晕层添加到按钮上
                layer.insertSublayer(glowLayer, at: 0)
            } else {
                // 移除所有光晕层
                layer.sublayers?.filter { $0.backgroundColor == UIColor.yellow.cgColor }.forEach { $0.removeFromSuperlayer() }
            }
        }
    }
}