user-interface - 圆角 SwiftUI

Question

我知道你可以使用 .cornerRadius()将 swiftUI View 的所有角都圆角，但有没有办法只圆角特定的角，例如顶部？

Answer 1

有两个选项，您可以使用 View与 Path ，或者您可以创建自定义 Shape .在这两种情况下，您都可以独立使用它们，或者在 .background(RoundedCorders(...)) 中使用它们。



选项 1:使用 Path + GeometryReader

(有关 GeometryReader 的更多信息:https://swiftui-lab.com/geometryreader-to-the-rescue/)

struct ContentView : View {
    var body: some View {

        Text("Hello World!")
            .foregroundColor(.white)
            .font(.largeTitle)
            .padding(20)
            .background(RoundedCorners(color: .blue, tl: 0, tr: 30, bl: 30, br: 0))
    }
}

struct RoundedCorners: View {
    var color: Color = .blue
    var tl: CGFloat = 0.0
    var tr: CGFloat = 0.0
    var bl: CGFloat = 0.0
    var br: CGFloat = 0.0

    var body: some View {
        GeometryReader { geometry in
            Path { path in

                let w = geometry.size.width
                let h = geometry.size.height

                // Make sure we do not exceed the size of the rectangle
                let tr = min(min(self.tr, h/2), w/2)
                let tl = min(min(self.tl, h/2), w/2)
                let bl = min(min(self.bl, h/2), w/2)
                let br = min(min(self.br, h/2), w/2)

                path.move(to: CGPoint(x: w / 2.0, y: 0))
                path.addLine(to: CGPoint(x: w - tr, y: 0))
                path.addArc(center: CGPoint(x: w - tr, y: tr), radius: tr, startAngle: Angle(degrees: -90), endAngle: Angle(degrees: 0), clockwise: false)
                path.addLine(to: CGPoint(x: w, y: h - br))
                path.addArc(center: CGPoint(x: w - br, y: h - br), radius: br, startAngle: Angle(degrees: 0), endAngle: Angle(degrees: 90), clockwise: false)
                path.addLine(to: CGPoint(x: bl, y: h))
                path.addArc(center: CGPoint(x: bl, y: h - bl), radius: bl, startAngle: Angle(degrees: 90), endAngle: Angle(degrees: 180), clockwise: false)
                path.addLine(to: CGPoint(x: 0, y: tl))
                path.addArc(center: CGPoint(x: tl, y: tl), radius: tl, startAngle: Angle(degrees: 180), endAngle: Angle(degrees: 270), clockwise: false)
            }
            .fill(self.color)
        }
    }
}

选项 2:自定义形状

struct ContentView : View {
    var body: some View {

        Text("Hello World!")
            .foregroundColor(.white)
            .font(.largeTitle)
            .padding(20)
            .background(RoundedCorners(tl: 0, tr: 30, bl: 30, br: 0).fill(Color.blue))
    }
}

struct RoundedCorners: Shape {
    var tl: CGFloat = 0.0
    var tr: CGFloat = 0.0
    var bl: CGFloat = 0.0
    var br: CGFloat = 0.0

    func path(in rect: CGRect) -> Path {
        var path = Path()

        let w = rect.size.width
        let h = rect.size.height

        // Make sure we do not exceed the size of the rectangle
        let tr = min(min(self.tr, h/2), w/2)
        let tl = min(min(self.tl, h/2), w/2)
        let bl = min(min(self.bl, h/2), w/2)
        let br = min(min(self.br, h/2), w/2)

        path.move(to: CGPoint(x: w / 2.0, y: 0))
        path.addLine(to: CGPoint(x: w - tr, y: 0))
        path.addArc(center: CGPoint(x: w - tr, y: tr), radius: tr,
                    startAngle: Angle(degrees: -90), endAngle: Angle(degrees: 0), clockwise: false)

        path.addLine(to: CGPoint(x: w, y: h - br))
        path.addArc(center: CGPoint(x: w - br, y: h - br), radius: br,
                    startAngle: Angle(degrees: 0), endAngle: Angle(degrees: 90), clockwise: false)

        path.addLine(to: CGPoint(x: bl, y: h))
        path.addArc(center: CGPoint(x: bl, y: h - bl), radius: bl,
                    startAngle: Angle(degrees: 90), endAngle: Angle(degrees: 180), clockwise: false)

        path.addLine(to: CGPoint(x: 0, y: tl))
        path.addArc(center: CGPoint(x: tl, y: tl), radius: tl,
                    startAngle: Angle(degrees: 180), endAngle: Angle(degrees: 270), clockwise: false)

        return path
    }
}