在 arc swift 上添加曲线

问题描述

我想以编程方式在一条线的中间生成一条曲线，但是使用我当前的解决方案不会使曲线的边缘变圆。

func createPath() -> CGPath {
    let height: CGFloat = 86.0
    let path = UIBezierPath()
    let centerWidth = self.frame.width / 2
    path.move(to: CGPoint(x: 0,y: 0))
    path.addLine(to: CGPoint(x: (centerWidth - (height/2)),y: 0))
    path.addArc(withCenter: CGPoint(x: centerWidth,y: 0),radius: 80 / 2,startAngle: 180 * CGFloat(PI)/180,endAngle: 0 * CGFloat(PI)/180,clockwise: false)
    path.addLine(to: CGPoint(x: self.frame.width,y: 0))
    path.addLine(to: CGPoint(x: self.frame.width,y: self.frame.height))
    path.addLine(to: CGPoint(x: 0,y: self.frame.height))
    path.lineCapStyle = .round
    path.stroke()
    path.close()
    self.path = path
    return path.cgPath
}

这是我创建的弧，但我希望曲线是圆角的：

但我希望它是这样的：

解决方法

这是您需要的代码

func createPath() -> CGPath {
let padding: CGFloat = 5.0
let centerButtonHeight: CGFloat = 53.0

let f = CGFloat(centerButtonHeight / 2.0) + padding
let h = frame.height
let w = frame.width
let halfW = frame.width/2.0
let r = CGFloat(18)
let path = UIBezierPath()
path.move(to: .zero)


path.addLine(to: CGPoint(x: halfW-f-(r/2.0),y: 0))

path.addQuadCurve(to: CGPoint(x: halfW-f,y: (r/2.0)),controlPoint: CGPoint(x: halfW-f,y: 0))

path.addArc(withCenter: CGPoint(x: halfW,radius: f,startAngle: .pi,endAngle: 0,clockwise: false)

path.addQuadCurve(to: CGPoint(x: halfW+f+(r/2.0),y: 0),controlPoint: CGPoint(x: halfW+f,y: 0))

path.addLine(to: CGPoint(x: w,y: 0))
path.addLine(to: CGPoint(x: w,y: h))
path.addLine(to: CGPoint(x: 0.0,y: h))
path.close()

return path.cgPath
}

结果：

您可以自定义按钮的大小...

关于它是如何工作的一个很好的解释，我建议你阅读这个解释，你可以画出你想要的任何形状：https://ayusinghi96.medium.com/draw-custom-shapes-and-views-with-uiberzierpath-ios-1737f5cb975

,

您可以像以前一样绘制更多弧线。或者你可以使用path.addCurve，如果你不想要椭圆形

    func createPath() -> CGPath {
        let bigRadius: CGFloat = 40.0
        let path = UIBezierPath()
        let centerWidth = self.frame.width / 2
        path.move(to: CGPoint(x: 0,y: 0))
        let radius: CGFloat = 4 //change it if you want
        let leftArcOriginX = centerWidth - bigRadius - radius
        let leftArcOriginY: CGFloat = 0
        path.addLine(to: CGPoint(x: leftArcOriginX,y: leftArcOriginY))
        // add left little arc,change angle if you want,if you dont want oval,may be you can use path.addCurve(to:,controlPoint1:,controlPoint2: )
        path.addArc(withCenter: CGPoint(x: leftArcOriginX,y: leftArcOriginY + radius),radius: radius,startAngle: CGFloat(270.0 * Double.pi/180.0),clockwise: true)
        // add big arc
        path.addArc(withCenter: CGPoint(x: centerWidth,y: radius),radius: bigRadius,startAngle: CGFloat(180.0 * Double.pi/180.0),endAngle: CGFloat(0 * Double.pi/180.0),clockwise: false)
        // add right litte arc
        path.addArc(withCenter: CGPoint(x: centerWidth + bigRadius + radius,endAngle: CGFloat(270.0 * Double.pi/180.0),clockwise: true)
        path.addLine(to: CGPoint(x: self.frame.width,y: 0))
        path.addLine(to: CGPoint(x: self.frame.width,y: self.frame.height))
        path.addLine(to: CGPoint(x: 0,y: self.frame.height))
        path.lineCapStyle = .round
        path.stroke()
        path.close()
        return path.cgPath
    }