Swift view渐变色简单实现

/// 渐变色

    lazy var gradLayer: CAGradientLayer = {         // 渐变色         let g = CAGradientLayer()         g.colors =  [UIColor.rgba(14, 21, 57, 0).cgColor,UIColor.rgba(14, 21, 57, 0.5).cgColor,UIColor.rgba(14, 21, 57, 0.5).cgColor,UIColor.rgba(6, 8, 22, 0).cgColor,UIColor.rgba(14, 21, 57, 0).cgColor] //渐变颜色

        g.locations = [0.2,0.5,0.8];//渐变起始位置

        g.startPoint = CGPoint.init(x: 0, y: 0)

        g.endPoint = CGPoint.init(x: 1, y: 0)         return g     }()

self.mainView.layer.addSublayer(gradLayer) DispatchQueue.main.asyncAfter(deadline: .now()) {           //  self.gradLayer.frame =  self.mainView.bounds         }