如何用SwiftUI绘制圆弧？

import SwiftUI

struct Arc: Shape {
    var startAngle: Angle
    var endAngle: Angle
    var clockwise: Bool

    func path(in rect: CGRect) -> Path {
        var path = Path()
        let center = CGPoint(x: rect.width / 2, y: rect.height / 2)
        let radius = min(rect.width, rect.height) / 2

        path.addArc(center: center, radius: radius, startAngle: startAngle, endAngle: endAngle, clockwise: clockwise)

        return path
    }
}

struct ContentView: View {
    var body: some View {
        Arc(startAngle: .degrees(0), endAngle: .degrees(180), clockwise: true)
            .stroke(Color.blue, lineWidth: 10)
            .frame(width: 200, height: 200)
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}