override func drawRect(rect: CGRect) {
        //绘制代码
}

let linePath = UIBezierPath()
linePath.move(to: CGPoint(x: 30, y: 50))
linePath.addLine(to: CGPoint(x: 190, y: 50))
UIColor.black.setStroke()   //设置边框颜色
linePath.lineWidth = 2      //设置线宽
linePath.stroke()           //绘制边框

//MARK:画一根虚线段
let dashLinePath = UIBezierPath()
dashLinePath.move(to: CGPoint(x: 30, y: 50))
dashLinePath.addLine(to: CGPoint(x: 190, y: 50))
UIColor.black.setStroke()
dashLinePath.lineWidth = 2

guard let context = UIGraphicsGetCurrentContext() as CGContext? else{ return }
context.saveGState()
context.setLineDash(phase: 0, lengths: [10,5])  //从0开始,循环地画:10个点跳5个点
dashLinePath.stroke()
context.restoreGState()

let breakenLinPath = UIBezierPath()
breakenLinPath.move(to: CGPoint(x: 30, y: 120))
breakenLinPath.addLine(to: CGPoint(x: 109.5, y: 90))
breakenLinPath.addLine(to: CGPoint(x: 190, y: 120))
UIColor.black.setStroke()
breakenLinPath.lineWidth = 2
breakenLinPath.stroke()

let curvePath = UIBezierPath()
curvePath.move(to: CGPoint(x: 30, y: 180))
curvePath.addCurve(to: CGPoint(x: 110, y: 140), controlPoint1: CGPoint(x: 30, y: 180), controlPoint2: CGPoint(x: 70, y: 140))
curvePath.addCurve(to: CGPoint(x: 190, y: 180), controlPoint1: CGPoint(x: 150, y: 140), controlPoint2: CGPoint(x: 190, y: 180))
UIColor.black.setStroke()
curvePath.lineWidth = 2
curvePath.stroke()

let rectangleRect = UIEdgeInsetsInsetRect(self.bounds, UIEdgeInsetsMake(20, 20, 20, 20))
let rectanglePath = UIBezierPath(rect: rectangleRect)
//填充颜色
UIColor.gray.setFill()
rectanglePath.fill()

let polygonRect = UIEdgeInsetsInsetRect(self.bounds, UIEdgeInsetsMake(20, 20, 20, 20))
let polygon3Path = UIBezierPath()
polygon3Path.move(to: CGPoint(x: polygonRect.minX + 100, y: polygonRect.minY + 40.5))
polygon3Path.addLine(to: CGPoint(x: polygonRect.minX + 151.53, y: polygonRect.minY + 129.75))
polygon3Path.addLine(to: CGPoint(x: polygonRect.minX + 48.47, y: polygonRect.minY + 129.75))
polygon3Path.close()
UIColor.green.setFill()
polygon3Path.fill()

let ovalRect = UIEdgeInsetsInsetRect(self.bounds, UIEdgeInsetsMake(20, 20, 20, 20))
let ovalPath = UIBezierPath(ovalIn: ovalRect)
 //MARK:填充颜色
UIColor.darkGray.setFill()
ovalPath.fill()

//填充图片
guard let context = UIGraphicsGetCurrentContext() as CGContext?,
    let image = UIImage(named: "image.png") as UIImage? else{
        return
}
context.saveGState()
ovalPath.addClip()
image.draw(in: ovalRect)
context.restoreGState()

//加边框
UIColor.green.setStroke()
ovalPath.lineWidth = 1
ovalPath.stroke()

let rectangleStyle = NSMutableParagraphStyle()  //段落样式集
rectangleStyle.alignment = .center

let rectangleFontAttributes = [NSFontAttributeName: UIFont(name: "HelveticaNeue", size: 12)!, NSForegroundColorAttributeName: UIColor.blue, NSParagraphStyleAttributeName: rectangleStyle]      //文字属性集

let textRect = UIEdgeInsetsInsetRect(self.bounds, UIEdgeInsetsMake(90, 20, 90, 20))

"Hello\nWorld".draw(in:textRect, withAttributes: rectangleFontAttributes)   //绘制到矩形框内