绘制透明圆形遮罩层和截取圆形中的图片

/// 截取遮罩层中镂空部分的内容生成图片
       @objc func handleSceenShot()  {
           UIGraphicsBeginImageContext(self.view.size)
           let context = UIGraphicsGetCurrentContext()
           let circlepath = UIBezierPath(roundedRect: CGRect(x: screenWidth() * 0.5 - 150, y: screenHight() * 0.5 - 150, width: 300, height:300), cornerRadius: 150)
           circlepath.addClip()
           self.view.layer .render(in: context!)
           let img = UIGraphicsGetImageFromCurrentImageContext()
           UIGraphicsEndImageContext()
           guard self.getImgFinish != nil else {
               return
           }
           guard img != nil else {return}
           self.getImgFinish!(img)
        }

/// 绘制圆形遮罩层
    func drawRoundLayer() {
        let bezierPath = UIBezierPath(roundedRect: self.view.bounds, cornerRadius: 0)
        let circlePath = UIBezierPath(roundedRect: CGRect(x: screenWidth() * 0.5 - 150, y: screenHight() * 0.5 - 150, width: 300, height:300), cornerRadius: 150)
        bezierPath.append(circlePath)
        bezierPath.usesEvenOddFillRule  = true
        
        let filleLayer = CAShapeLayer()
        filleLayer.path = bezierPath.cgPath
        filleLayer.fillRule = CAShapeLayerFillRule.evenOdd
        filleLayer.opacity = 0.5
        self.view.layer .addSublayer(filleLayer)
    }