iOS实现抖音点赞动画效果

import UIKit
 
public class LikeView: UIView {
 
 // 红色爱心视图
 fileprivate var likeImageView = UIImageView()
 // 白色爱心视图
 fileprivate var unLikeImageView = UIImageView()
 // true: 点赞， false：取消点赞
 fileprivate var isLike: Bool = false
 // 动画时长，可设置
 public var duration: CFTimeInterval = 0.5
 
 override init(frame: CGRect) {
 super.init(frame: frame)
 setupUI()
 }
 
 required init?(coder: NSCoder) {
 super.init(coder: coder)
 setupUI()
 }
 
 fileprivate func setupUI() {
 // 添加白色爱心视图
 unLikeImageView.frame = CGRect(x: 0, y: 0, width: frame.size.width, height: frame.size.height)
 unLikeImageView.image = UIImage(named: "icon_like_before")
 addSubview(unLikeImageView)
 
 // 添加红色爱心视图，并设置不可看。切记红色爱心在在白色爱心的上面。
 likeImageView.frame = CGRect(x: 0, y: 0, width: frame.size.width, height: frame.size.height)
 likeImageView.image = UIImage(named: "icon_like_after")
 likeImageView.alpha = 0
 addSubview(likeImageView)
 
 // 添加单击手势
 let tap = UITapGestureRecognizer(target: self, action: #selector(tapLikeAction))
 self.addGestureRecognizer(tap)
 }
 
 // 点击事件
 @objc fileprivate func tapLikeAction() {
 // 点击的时候停止交互，以免反复点击。
 self.isUserInteractionEnabled = false
 isLike = !isLike
 
 // 点赞
 if isLike {
 // 设置红色爱心不可见
 likeImageView.alpha = 0
 
 // 将红色爱心缩小至原来0.2倍。
 self.likeImageView.transform = CGAffineTransform(scaleX: 0.2, y: 0.2)
 
 
 
 UIView.animate(withDuration: duration * 0.3, delay: 0, options: .curveEaseInOut) { [weak self] in
 // 将白色爱心逐渐变小至0.2倍，
 self?.unLikeImageView.transform = CGAffineTransform(scaleX: 0.2, y: 0.2)
 } completion: { [weak self] (finished) in
 // 设置红色爱心可见，此时是0.2倍大小。
 self?.likeImageView.alpha = 1
 let duration = self?.duration ?? 0.5
 // 白色爱心变小后，继续操作红色爱心
 UIView.animate(withDuration: duration * 0.7, delay: 0.1, usingspringWithDamping: 0.6, initialSpringVelocity: 0.8, options: .curveEaseInOut) {
  // 将红色爱心恢复原大小
  self?.likeImageView.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
 } completion: { (finished) in
  // 红色爱心变大后，恢复白色爱心的尺寸，开启用户交互。
  self?.unLikeImageView.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
  self?.isUserInteractionEnabled = true
 }
 }
 
 //
 
 // 小圆环路径
 let circleStartPath = UIBezierPath(arcCenter: likeImageView.layer.position, radius: self.bounds.size.width / 6, startAngle: 0, endAngle: CGFloat(2*Double.pi), clockwise: true)
 
 // 大圆环路径
 let radius = sqrt(powf(Float(self.bounds.size.width), 2) + powf(Float(self.bounds.size.height), 2))/2
 let circleEndPath = UIBezierPath(arcCenter: likeImageView.layer.position, radius: CGFloat(radius), startAngle: 0, endAngle: CGFloat(2*Double.pi), clockwise: true)
 
 // 创建圆环图层，用于显示圆环。
 let circleLayer = CAShapeLayer()
 circleLayer.strokeColor = UIColor.red.cGColor
 circleLayer.fillColor = UIColor.clear.cgColor
 self.layer.insertSublayer(circleLayer, below: self.likeImageView.layer)
 
 // 计算圆环图层的偏移时间
 var currentTimeInSuper = self.layer.convertTime(CACurrentMediaTime(), from: nil)
 var currentTimeLocal = circleLayer.convertTime(currentTimeInSuper, from: self.layer)
 
 // 设置圆环动画组执行时间
 let circleGroupDuration = duration * 0.5
 
 // 圆环动画组
 let circleGroup = CAAnimationGroup()
 circleGroup.duration = circleGroupDuration
 // 圆环动画组开始时间，此开始时间正好是白色爱心变小后，红色爱心开始变大时。
 circleGroup.beginTime = currentTimeLocal + duration * 0.3
 
 // 设置圆环路径变化动画
 let circlePathAnimation = CABasicAnimation(keyPath: "path")
 circlePathAnimation.fromValue = circleStartPath.cgPath
 circlePathAnimation.toValue = circleEndPath.cgPath
 
 // 设置圆环宽度变化动画，先变大，再变小。
 let circleLineWidthAnimation = CAKeyframeAnimation(keyPath: "lineWidth")
 circleLineWidthAnimation.values = [1.0, 4.0, 0.3]
 circleLineWidthAnimation.keyTimes = [0.0, 0.7, 0.9]
 
 // 将圆环的两个动画添加到动画组。
 circleGroup.animations = [circlePathAnimation, circleLineWidthAnimation]
 
 // 将动画添加到圆环图层。
 circleLayer.add(circleGroup, forKey: nil)
 //
 
 //
 // 循环创建三角形图层，并添加动画效果
 for i in 0..<6 {
 // 三角形的高
 let height = self.bounds.size.height / 2 + 12
 // 三角形底边长
 let width = self.bounds.size.width / 10
 
 // 绘制一个起始三角形路径
 let triangleStartPath = UIBezierPath()
 triangleStartPath.move(to: .zero)
 triangleStartPath.addLine(to: CGPoint(x: -1, y: -1))
 triangleStartPath.addLine(to: CGPoint(x: 1, y: -1))
 triangleStartPath.close()
 
 // 绘制一个完全展开的三角形路径
 let triangleMiddlePath = UIBezierPath()
 triangleMiddlePath.move(to: .zero)
 triangleMiddlePath.addLine(to: CGPoint(x: -width/2, y: -height))
 triangleMiddlePath.addLine(to: CGPoint(x: width/2, y: -height))
 triangleMiddlePath.close()
 
 // 绘制一个终了三角形路径
 let triangleEndPath = UIBezierPath()
 triangleEndPath.move(to: CGPoint(x: 0, y: -height))
 triangleEndPath.addLine(to: CGPoint(x: -width/2, y: -height))
 triangleEndPath.addLine(to: CGPoint(x: width/2, y: -height))
 triangleEndPath.close()
 
 // 绘制三角形图层
 let shapeLayer = CAShapeLayer()
 // 设置图层中心位置，很重要。
 shapeLayer.position = self.likeImageView.layer.position
 shapeLayer.fillColor = UIColor.red.cgColor
 // 将图层进行旋转。
 shapeLayer.transform = CATransform3DMakeRotation(CGFloat(Double.pi/3) * CGFloat(i), 0, 0, 1)
 
 self.layer.insertSublayer(shapeLayer, below: circleLayer)
 
 // 计算三角形图层的偏移时间
 currentTimeInSuper = self.layer.convertTime(CACurrentMediaTime(), from: nil)
 currentTimeLocal = shapeLayer.convertTime(currentTimeInSuper, from: self.layer)
 
 // 设置三角形的动画，由小变大再变小。
 let trianglePathAnimation = CAKeyframeAnimation(keyPath: "path")
 trianglePathAnimation.values = [triangleStartPath.cgPath, triangleMiddlePath.cgPath, triangleEndPath.cgPath]
 trianglePathAnimation.keyTimes = [0.0, 0.3, 0.7]
 trianglePathAnimation.duration = duration * 0.7
 trianglePathAnimation.beginTime = currentTimeLocal + duration * 0.3
 
 shapeLayer.add(trianglePathAnimation, forKey: nil)
 }
 //
 }else {
 // 取消点赞
 // 1. 将红色爱心逐渐缩小至原来的0.1倍，然后设置为不可见并恢复原尺寸大小。
 UIView.animate(withDuration: duration * 0.3, delay: 0, options: .curveEaseInOut) { [weak self] in
 self?.likeImageView.transform = CGAffineTransform(scaleX: 0.1, y: 0.1)
 } completion: { [weak self] (finished) in
 self?.likeImageView.alpha = 0
 self?.likeImageView.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
 self?.isUserInteractionEnabled = true
 }
 }
 }
}

class ViewController: UIViewController {
 
 override func viewDidLoad() {
 super.viewDidLoad()
 view.backgroundColor = UIColor.black
 // 设置一个0.5秒的动画
 let likeView1 = LikeView(frame: CGRect(x: 110, y: 300, width: 50, height: 50))
 likeView1.duration = 0.5
 self.view.addSubview(likeView1)
 
 // 设置一个10秒的动画
 let likeView2 = LikeView(frame: CGRect(x: 240, y: 300, width: 50, height: 50))
 likeView2.duration = 10
 self.view.addSubview(likeView2)
 }
 
}