swift4--视图的填充与仿射变换

视图的渐变填充

//创建一个矩形视图
let gradientview = UIView(frame: CGRect(x: 30, y: 60, width: 200, height: 200))

//创建一个渐变层视图
let gradientLayer = CAGradientLayer()

//设置渐变层显示区域与原视图相等
gradientLayer.frame = gradientview.frame

//设置渐变过渡颜色
let fromColor = UIColor.yellow.cgColor

let midColor = UIColor.red.cgColor

let toColor = UIColor.purple.cgColor

gradientLayer.colors = [fromColor, midColor, toColor]

//把配置好的渐变层添加到视图对象的层中
view.layer.addSublayer(gradientLayer)

self.view.addSubview(gradientview)

视图的纹理填充

let img = UIImage(named: "wenli")

//新建一个颜色对象，将导入的图片赋予该对象
let patternColor = UIColor.init(patternImage: img!)

//将此颜色赋值给当前视图控制器根视图
self.view.backgroundColor = patternColor

仿射变换

let view = UIView(frame: CGRect(x: 50, y: 150, width: 200, height: 50))
view.backgroundColor = UIColor.brown

self.view.addSubview(view)

//创造一个仿射变换变量（可以用于平移，旋转，缩放变换路径或者图形上下文）
var transform = view.transform

// 缩放
view.transform = CGAffineTransform(scaleX: 2, y: 2)

// 旋转
view.transform = CGAffineTransform(rotationAngle: CGFloat.pi / 2)

// 平移
view.transform = CGAffineTransform(translationX: 100, y: 100)

        
view.transform = transform