ios – 如何对齐UIBezierPath圆圈破折号

我正在尝试使用UIBezierPath绘制一个指南针并在该线上添加破折号以标记其中的北,南,东,西方向和点.破折号似乎是偏移的(它们没有对齐),特别是在北方和南方方向,而我正在做的方式似乎在路径关闭时添加了额外的破折号.

let windCircleOrigin = CGPoint(x: self.center.x * 1.3,y: self.bounds.height / 2.0 - 10)
let windCircleRadius = CGFloat(self.bounds.height * 0.3)
let windCirclePath: UIBezierPath = UIBezierPath(arcCenter: windCircleOrigin,radius: windCircleRadius,startAngle: 0,endAngle: CGFloat(M_PI) * 2.0,clockwise: true)
        windCirclePath.linewidth = 6
let dashes: [CGFloat] = [windCirclePath.linewidth * 0,windCirclePath.linewidth * 3 ]
        windCirclePath.setLineDash(dashes,count: dashes.count,phase: 0.0)
UIColor.whiteColor().setFill()
UIColor.whiteColor().setstroke()
windCirclePath.stroke()
textView(self.windSpeedLabel! + " mph",x: windCircleOrigin.x - 20.0,y: windCircleOrigin.y - 8.0,color: UIColor.whiteColor(),width: 50.0,height: 20.0)
textView("N",x: windCircleOrigin.x - 7.0,y: windCircleOrigin.y - 70.0,width: 20,height: 20)
textView("S",y: windCircleOrigin.y + 50.0,height: 20)
textView("W",x: windCircleOrigin.x - 70.0,height: 20)
textView("E",x: windCircleOrigin.x + 60.0,height: 20)

func textView(text: String,x: CGFloat,y: CGFloat,color: UIColor,width: CGFloat,height: CGFloat) {
    let textView = UILabel(frame: CGRectMake(x,y,width,height))
    textView.textAlignment = NSTextAlignment.Left
    textView.textColor = color
    textView.backgroundColor = UIColor.clearColor()
    textView.font = UIFont(name: "HelveticaNeue-Light",size: 12.0)
    textView.text = text
    self.addSubview(textView)
}

解决方法

相反,我建议单独绘制每个刻度.然后你可以轻松控制他们的位置.

像这样的东西：

let path = UIBezierPath()
let innerRadius: CGFloat = 50
let outerRadius: CGFloat = 60
let numTicks = 24

for i in 0..<numTicks {
    let angle = CGFloat(i) * CGFloat(2*M_PI) / CGFloat(numTicks)
    let inner = CGPoint(x: innerRadius * cos(angle),y: innerRadius * sin(angle))
    let outer = CGPoint(x: outerRadius * cos(angle),y: outerRadius * sin(angle))
    path.movetoPoint(inner)
    path.addLinetoPoint(outer)
}

然后,您可以使用所需的任何linewidth(和lineCapStyle)来描述此路径.