斯威夫特4斯威夫特5简单的方式在一行

用法:

//MARK:- Corner Radius of only two side of UIViews
self.roundCorners(view: yourview, corners: [.bottomLeft, .topRight], radius: 12.0)

功能:

//MARK:- Corner Radius of only two side of UIViews
func roundCorners(view :UIView, corners: UIRectCorner, radius: CGFloat){
        let path = UIBezierPath(roundedRect: view.bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
        let mask = CAShapeLayer()
        mask.path = path.cgPath
        view.layer.mask = mask
}

在objective - c中

用法:

[自我。verticalSeparatorView roundCorners: UIRectCornerTopLeft | UIRectCornerTopRight半径:10 0];

在Category中使用的函数(只有一个角):

-(void)roundCorners: (UIRectCorner) corners radius:(CGFloat)radius {
        UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:self.bounds byRoundingCorners:corners cornerRadii:CGSizeMake(radius, radius)];
        CAShapeLayer *mask = [[CAShapeLayer alloc] init];
        mask.path = path.CGPath;
        self.layer.mask = mask;
    }

最简单的方法是用圆角层做一个蒙版。

CALayer *maskLayer = [CALayer layer];
maskLayer.frame = CGRectMake(0,0,maskWidth ,maskHeight);
maskLayer.contents = (__bridge id)[[UIImage imageNamed:@"maskImageWithRoundedCorners.png"] CGImage];

aUIView.layer.mask = maskLayer;

别忘了:

#import <QuartzCore/QuartzCore.h>

一个可爱的扩展重用尤努斯Nedim Mehel解决方案

斯威夫特2.3

extension UIView {
func roundCornersWithLayerMask(cornerRadii: CGFloat, corners: UIRectCorner) {
    let path = UIBezierPath(roundedRect: bounds,
                            byRoundingCorners: corners,
                            cornerRadii: CGSize(width: cornerRadii, height: cornerRadii))
    let maskLayer = CAShapeLayer()
    maskLayer.path = path.CGPath
    layer.mask = maskLayer
} }

使用

let view = UIView()
view.roundCornersWithLayerMask(10,[.TopLeft,.TopRight])

Stephane回答的另一个版本。

import UIKit

    class RoundCornerView: UIView {
    var corners : UIRectCorner = [.topLeft,.topRight,.bottomLeft,.bottomRight]
        var roundCornerRadius : CGFloat = 0.0
        override func layoutSubviews() {
            super.layoutSubviews()
            if corners.rawValue > 0 && roundCornerRadius > 0.0 {
                self.roundCorners(corners: corners, radius: roundCornerRadius)
            }
        }
        private func roundCorners(corners: UIRectCorner, radius: CGFloat) {
            let path = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
            let mask = CAShapeLayer()
            mask.path = path.cgPath
            layer.mask = mask
        }

    }

在Swift 4.1和Xcode 9.4.1中

在iOS 11中，这一行就足够了:

detailsSubView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]//Set your view here

查看完整代码:

//In viewDidLoad
if #available(iOS 11.0, *) {
        detailsSubView.clipsToBounds = false
        detailsSubView.layer.cornerRadius = 10
        detailsSubView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
} else {
      //For lower versions
}

但是对于低版本

let rectShape = CAShapeLayer()
    rectShape.bounds = detailsSubView.frame
    rectShape.position = detailsSubView.center
    rectShape.path = UIBezierPath(roundedRect: detailsSubView.bounds,    byRoundingCorners: [.topLeft , .topRight], cornerRadii: CGSize(width: 20, height: 20)).cgPath
    detailsSubView.layer.mask = rectShape

完整的代码是。

if #available(iOS 11.0, *) {
    detailsSubView.clipsToBounds = false
    detailsSubView.layer.cornerRadius = 10
    detailsSubView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
} else {
    let rectShape = CAShapeLayer()
    rectShape.bounds = detailsSubView.frame
    rectShape.position = detailsSubView.center
    rectShape.path = UIBezierPath(roundedRect: detailsSubView.bounds,    byRoundingCorners: [.topLeft , .topRight], cornerRadii: CGSize(width: 20, height: 20)).cgPath
    detailsSubView.layer.mask = rectShape
}

如果你在故事板中使用AutoResizing，请在viewDidLayoutSubviews()中编写以下代码。

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()

    if #available(iOS 11.0, *) {
        detailsSubView.clipsToBounds = false
        detailsSubView.layer.cornerRadius = 10
        detailsSubView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
    } else {
        let rectShape = CAShapeLayer()
        rectShape.bounds = detailsSubView.frame
        rectShape.position = detailsSubView.center
        rectShape.path = UIBezierPath(roundedRect: detailsSubView.bounds,    byRoundingCorners: [.topLeft , .topRight], cornerRadii: CGSize(width: 20, height: 20)).cgPath
        detailsSubView.layer.mask = rectShape
    }
}

对于 SwiftUI

我找到了这些解决方案，你可以在这里查看https://stackoverflow.com/a/56763282/3716103

我强烈推荐第一个

选项1:使用Path + GeometryReader

(更多关于GeometryReader的信息: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))
    }
}

RoundedCorners

struct RoundedCorners: View {

    var color: Color = .white

    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 - be))
                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)
        }
    }
}

RoundedCorners_Previews

struct RoundedCorners_Previews: PreviewProvider {
    static var previews: some View {
        RoundedCorners(color: .pink, tl: 40, tr: 40, bl: 40, br: 40)
    }
}