UIBezierPath在处理闭合图形时执行此操作。

UIBezierPath *firstPath = [UIBezierPath bezierPath];
// build your path

UIBezierPath *secondPath = [UIBezierPath bezierPath];
// build your path

[firstPath appendPath:secondPath];

如果您的部署目标是iOS 16（或macOS 13）或更高版本，您可以使用union方法计算两个CGPath对象的并集，如下所示：

let path1: CGPath = ...
let path2: CGPath = ...
let combo = path1.union(path2)

在Swift 3中，Bezier路径可以通过以下方式统一：

override func draw(_ rect: CGRect) {
    super.draw(rect)

    UIColor.black.setStroke()
    UIColor.red.setFill()

    let currentContext = UIGraphicsGetCurrentContext()
    currentContext?.saveGState() 

    let path = drawTopView()
    path.lineWidth = 5.0
    path.fill()
    path.stroke()

    let middlepath = drawMiddleView()
    middlepath.lineWidth = 2.0
    middlepath.fill()
    middlepath.stroke()

    path.append(middlepath)
    currentContext?.restoreGState()
}

快速用户界面

func createView() -> some View {
    let a = Path { path in
        path.move(to: CGPoint(x: 0, y: 0))
        path.addLine(to: CGPoint(x: 50, y: 100))
        path.addLine(to: CGPoint(x: 100, y: 0))
    }
    .stroke(Color.white, style: StrokeStyle(lineWidth: 5, lineCap: .round, lineJoin: .round))

    let b = RoundedRectangle(cornerRadius: 5, style: .continuous)
        .fill(Color.white)
        .frame(width: 30, height: 30)
        .position(CGPoint.zero)

    return ZStack {
        a
        b
    }
    .compositingGroup()
    .colorMultiply(Color.red)
}