有没有办法为一个UIView的左上角和右上角设置角半径?

我尝试了下面的方法,但最终它再也看不到视图了。

UIView *view = [[UIView alloc] initWithFrame:frame];

CALayer *layer = [CALayer layer];
UIBezierPath *shadowPath = [UIBezierPath bezierPathWithRoundedRect:frame byRoundingCorners:(UIRectCornerTopLeft|UIRectCornerTopRight) cornerRadii:CGSizeMake(3.0, 3.0)];
layer.shadowPath = shadowPath.CGPath;
view.layer.mask = layer;

当前回答

在swift 4.3中,修改代码后@apinho工作正常

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
  }
}

为您的视图使用此函数

YourViewName. roundCornersWithLayerMask(cornerRadii: 20,corners: [.topLeft,.topRight])

其他回答

在swift 4.3中,修改代码后@apinho工作正常

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
  }
}

为您的视图使用此函数

YourViewName. roundCornersWithLayerMask(cornerRadii: 20,corners: [.topLeft,.topRight])

iOS 11, Swift 4 你可以试试这段代码:

if #available(iOS 11.0, *) {
   element.clipsToBounds = true
   element.layer.cornerRadius = CORNER_RADIUS
   element.layer.maskedCorners = [.layerMaxXMaxYCorner]
} else {
   // Fallback on earlier versions
}

你可以在表格视图单元格中使用这个。

这是如何在c#中使用Xamarin为按钮的每个角落设置角半径:

var maskPath = UIBezierPath.FromRoundedRect(MyButton.Bounds, UIRectCorner.BottomLeft | UIRectCorner.BottomRight,
    new CGSize(10.0, 10.0));
var maskLayer = new CAShapeLayer
{
    Frame = MyButton.Bounds,
    Path = maskPath.CGPath
};
MyButton.Layer.Mask = maskLayer;

只查看toppleft和TopRight角半径

lazy var footerBackgroundView: UIView = {

    let view = UIView()
    view.translatesAutoresizingMaskIntoConstraints = false
    view.backgroundColor = .blue

    //Make Corners Radius TopLeft & Top Right
    view.clipsToBounds = true
    view.layer.cornerRadius = 8
    view.layer.maskedCorners = [.layerMaxXMinYCorner, .layerMinXMinYCorner] 
    
    return view
}()

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
        }

    }