ios swift UIView 设置渐变 UIView

直接代码记录

/// 渐变色view， 带有渐变效果的View, 方便调用

class LZGradientView: UIView {
    private(set) var colors: [CGColor] = []
    private(set) var direction: BBGradientColorDirection = .topToBottom

    public func setColors( colors: [CGColor],

                           direction: BBGradientColorDirection = .topToBottom)  {

        self.direction = direction
        self.colors = colors
        self.setGradientLayer()
    }

    func setGradientLayer() {
        // add layer

        let gradientLayer = self.layer as? CAGradientLayer  //重要 直接用 self.layer

        gradientLayer?.colors = self.colors

        // locations

//        gradientLayer?.locations = [0, 1]

        // start, end point

        switch direction {

        case .topToBottom:

            gradientLayer?.startPoint = CGPoint(x: 0, y: 0)

            gradientLayer?.endPoint = CGPoint(x: 0, y: 1)

        case .bottomToTop:

            gradientLayer?.startPoint = CGPoint(x: 0, y: 1)

            gradientLayer?.endPoint = CGPoint(x: 0, y: 0)

        case .leftToRight:

            gradientLayer?.startPoint = CGPoint(x: 0, y: 0)

            gradientLayer?.endPoint = CGPoint(x: 1, y: 0)

        case .rightToLeft:

            gradientLayer?.startPoint = CGPoint(x: 1, y: 0)

            gradientLayer?.endPoint = CGPoint(x: 0, y: 0)

        case .rightTopToLeftBottom:

            gradientLayer?.startPoint = CGPoint(x: 1, y: 0)

            gradientLayer?.endPoint = CGPoint(x: 0, y: 1)

        case .leftTopToRightBottom:

            gradientLayer?.startPoint = CGPoint(x: 0, y: 0)

            gradientLayer?.endPoint = CGPoint(x: 1, y: 1)

        }

    }

}