ios - 快速自定义UIBezierPath(Arc麻烦)

我写这段代码：

let leftUpPath = UIBezierPath()
leftUpPath.move(to: CGPoint(x: 40, y: 40))
leftUpPath.addArc(withCenter: CGPoint(x: 40, y: 40),
    radius: 10,
    startAngle: CGFloat(Double.pi),
    endAngle: CGFloat(3*Double.pi),
    clockwise: true)
leftUpPath.addLine(to: CGPoint(x: 30, y: 50))
leftUpPath.addLine(to: CGPoint(x: 90, y: 50))
leftUpPath.addLine(to: CGPoint(x: 80, y: 30))
leftUpPath.addLine(to: CGPoint(x: 40, y: 30))

这个在我的故事板上给我看：
但我想要这个：
如果有人有办法的话，我想我的麻烦就在我画弧线的地方。。。谢谢你的帮助

最佳答案

第一个点和弧不正确。你需要：

let leftUpPath = UIBezierPath()
leftUpPath.move(to: CGPoint(x: 40, y: 30))
leftUpPath.addArc(withCenter: CGPoint(x: 40, y: 40),
                  radius: 10,
                  startAngle: .pi * 3 / 2,
                  endAngle: .pi,
                  clockwise: false)
leftUpPath.addLine(to: CGPoint(x: 30, y: 50))
leftUpPath.addLine(to: CGPoint(x: 90, y: 50))
leftUpPath.addLine(to: CGPoint(x: 80, y: 30))
leftUpPath.addLine(to: CGPoint(x: 40, y: 30))