标签：device line creat ret src tom 详情 sys tps
第一种实现方案：使用图层layer实现
层级结构如图所示：
构建过程如下：
//添加渐变色图层gradientLayer
let gradientLayer = CAGradientLayer()
gradientLayer.colors = [UIColor(hex: "4DABF4").cgColor, UIColor(hex: "9B30C1").cgColor]
//(I.e. [0,0] is the bottom-left corner of the layer, [1,1] is the top-right corner.)
gradientLayer.startPoint = CGPoint(x: 0, y: 0)
gradientLayer.endPoint = CGPoint(x: 1, y: 0)
gradientLayer.position = CGPoint(x: width*0.5, y: height*0.5)
gradientLayer.bounds = CGRect(origin: CGPoint.zero, size: CGSize(width: width, height: height))
self.layer.insertSublayer(gradientLayer, at: 0)
lazy var contextLabel: UILabel = { let label = UILabel() label.text = " %" label.font = UIFont.systemFont(ofSize: 12) label.textColor = UIColor.white label.textAlignment = NSTextAlignment.center label.backgroundColor = UIColor.clear return label }() contextLabel.frame = CGRect(x: 0, y: 0, width: width, height: height) self.addSubview(contextLabel)
func maskLayer() { let temp = CGPoint(x: 0, y: 0) let bez = UIBezierPath() bez.move(to: temp) bez.addLine(to: CGPoint(x: progressWidth, y: 0)) bez.addArc(withCenter: CGPoint(x: progressWidth, y: height*0.5), radius: height*0.5, startAngle: -CGFloat(M_PI_2), endAngle: CGFloat(M_PI_2), clockwise: true) bez.addLine(to: CGPoint(x: 0, y: height)) bez.close() msLayer.path = bez.cgPath bottomLayer!.mask = msLayer }
画弧时顺时针方向问题：
CoreGraphics的坐标系弧度，与顺时针方向如图所示，注意不要用错了：
let context = UIGraphicsGetCurrentContext() //渐变色 let colorSpace = CGColorSpaceCreateDeviceRGB() let locations:[CGFloat] = [0,1] let startC = UIColor(hex: "EEA13A") let endC = UIColor(hex: "B1283C") let colors = [startC.cgColor,endC.cgColor] let gradient = CGGradient(colorsSpace: colorSpace, colors: colors as CFArray, locations: locations) context?.drawLinearGradient(gradient!, start: CGPoint(x: 0, y: 0), end: CGPoint(x: rect.size.width, y: 0), options: CGGradientDrawingOptions.drawsBeforeStartLocation) //渐变色弧 context?.saveGState() context?.addRect(rect) context?.move(to: CGPoint(x: width-edgeDistance, y: bigOuterRadius)) context?.addArc(center: arcCenter, radius: bigOuterRadius, startAngle: 0, endAngle: CGFloat(M_PI), clockwise: true) context?.addArc(center: CGPoint(x: smailRadius+edgeDistance, y: arcCenter.y), radius: smailRadius, startAngle: CGFloat(M_PI), endAngle: CGFloat(M_PI*2), clockwise: true) context?.addArc(center: arcCenter, radius: bigInnerRadius, startAngle: CGFloat(M_PI), endAngle: CGFloat(M_PI*2), clockwise: false) context?.addArc(center: CGPoint(x: width-smailRadius-edgeDistance, y: arcCenter.y), radius: smailRadius, startAngle: CGFloat(M_PI), endAngle: CGFloat(M_PI*2), clockwise: true) context?.setFillColor(UIColor.white.cgColor) context?.fillPath() //灰色弧 context?.restoreGState() let context1 = UIGraphicsGetCurrentContext() var endAng = CGFloat(M_PI*2) - (_progressValue * CGFloat(M_PI)) context1?.move(to: CGPoint(x: width-edgeDistance, y: bigOuterRadius)) context1?.addArc(center: arcCenter, radius: bigOuterRadius, startAngle: 0, endAngle: endAng, clockwise: true) let midSmallX: CGFloat = arcCenter.x + cos(endAng)*(bigOuterRadius-smailRadius) let midSmallY: CGFloat = arcCenter.y + sin(endAng)*(bigOuterRadius-smailRadius) context1?.addArc(center: CGPoint(x: midSmallX, y: midSmallY), radius: smailRadius, startAngle: endAng, endAngle: endAng-CGFloat(M_PI), clockwise: false) context1?.addArc(center: arcCenter, radius: bigInnerRadius, startAngle: endAng, endAngle: CGFloat(M_PI*2), clockwise: false) context1?.addArc(center: CGPoint(x: width-smailRadius-edgeDistance, y: arcCenter.y), radius: smailRadius, startAngle: CGFloat(M_PI), endAngle: CGFloat(M_PI*2), clockwise: true) context1?.setFillColor(UIColor(hex: "e7e3e3").cgColor) context1?.fillPath()
标签：device line creat ret src tom 详情 sys tps
原文地址：https://www.cnblogs.com/zhou--fei/p/10182351.html
