iOS之UIView的渐变填充和纹理填充（Swift 4.2)

版权声明：Created by 影子传说 // Copyright © 2018年 影子传说. All rights reserved. https://blog.csdn.net/jaydneg23333/article/details/82824392

 UIview的渐变填充：

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
//        UIView的渐变填充
        let rect = CGRect(x: 30, y: 60, width: 200, height: 200)
        let gradientView = UIView(frame: rect)

        let gradientLayer = CAGradientLayer()  //新建一个渐变层
        gradientLayer.frame = gradientView.frame

        let fromColor = UIColor.yellow.cgColor
        let midColor = UIColor.red.cgColor
        let toColor = UIColor.purple.cgColor

        gradientLayer.colors = [fromColor,midColor,toColor]//将渐变层的颜色属性设置为由三个颜色所构建的数组

        view.layer.addSublayer(gradientLayer) //将设置好的渐变层添加到视图对象的层中
        self.view.addSubview(gradientView)//将试图对象添加到根视图
    }
}

UIview的纹理填充：

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

    //UIView视图的纹理填充
        let image = UIImage(named:"cat")
        //新建一个颜色对象 并将“cat”图片赋予该对象
        let patternColor = UIColor.init(patternImage: image!)//UIImage 为可选项类型
        self.view.backgroundColor = patternColor//将此颜色对象赋值为根视图的背景
    }
}