Swift — 给一个UIView添加红心跳动

给红心❤️ UIview 添加动画，模仿心跳，放大缩小的动画。

    /// 红心跳动
    var heartImage = UIImageView(image: UIImage(named: "vivi_videocall_match_redheart"))
    func redHeartMove() {
        view.addSubview(heartImage)
        heartImage.snp.makeConstraints { (make) in
            make.bottom.equalTo(-120)
            make.width.height.equalTo(90)
            make.centerX.equalToSuperview()
        }
        
        let k = CAKeyframeAnimation(keyPath: "transform.scale")
        k.values = [0.9, 1.0,1.1]
        k.keyTimes = [0.0, 0.2, 0.6, 0.8, 1.0]
        k.calculationMode = .linear
        k.repeatCount = 1000
        k.duration = 1.5
        heartImage.layer.add(k, forKey: "SHOW")
    }