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

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>

其他回答

在Swift 4.2中,通过@IBDesignable创建它,如下所示:

@IBDesignable

class DesignableViewCustomCorner: UIView {

    @IBInspectable var cornerRadious: CGFloat = 0 {
        didSet {
            let path = UIBezierPath(roundedRect: self.bounds, byRoundingCorners: [.topLeft, .topRight], cornerRadii: CGSize(width: cornerRadious, height: cornerRadious))
            let mask = CAShapeLayer()
            mask.path = path.cgPath
            self.layer.mask = mask
        }
    }

}
    // Create the path (with only the top-left corner rounded)
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds 
                           byRoundingCorners:(UIRectCornerBottomLeft | UIRectCornerBottomRight) 
                           cornerRadii:CGSizeMake(7.0, 7.0)];

// Create the shape layer and set its path
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = cell.stripBlackImnageView.bounds;
maskLayer.path = maskPath.CGPath; 
// Set the newly created shapelayer as the mask for the image view's layer
view.layer.mask = maskLayer;

这是最简单的答案:

yourView.layer.cornerRadius = 8
yourView.layer.masksToBounds = true
yourView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]

使用这个扩展设置角圆角和圆角边界

像这样使用:

override func viewWillLayoutSubviews() {
            super.viewWillLayoutSubviews()

         myView.roundCornersWithBorder(corners: [.topLeft, .topRight], radius: 8.0)
    
        myView.roundCorners(corners: [.topLeft, .topRight], radius: 8.0)

        }



extension UIView {
   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
    }
    
    func roundCornersWithBorder(corners: UIRectCorner, radius: CGFloat) {
        let maskLayer = CAShapeLayer()
        maskLayer.frame = bounds
        maskLayer.path = UIBezierPath(roundedRect: bounds, byRoundingCorners: [.topLeft, .topRight], cornerRadii: CGSize(width: radius, height: radius)).cgPath
        
        layer.mask = maskLayer
        
        // Add border
        let borderLayer = CAShapeLayer()
        borderLayer.path = maskLayer.path // Reuse the Bezier path
        borderLayer.fillColor = UIColor.clear.cgColor
        borderLayer.strokeColor = UIColor(red:3/255, green:33/255, blue:70/255, alpha: 0.15).cgColor
        borderLayer.lineWidth = 2
        borderLayer.frame = bounds
        layer.addSublayer(borderLayer)
    }
    
}

以下是Swift 5的最佳方法:

import UIKit

extension UIView {

func roundCorners(radius: CGFloat = 10, corners: UIRectCorner = .allCorners) {
        self.clipsToBounds = true
        self.layer.cornerRadius = radius
        if #available(iOS 11.0, *) {
            var arr: CACornerMask = []
            
            let allCorners: [UIRectCorner] = [.topLeft, .topRight, .bottomLeft, .bottomRight, .allCorners]
            
            for corn in allCorners {
                if(corners.contains(corn)){
                    switch corn {
                    case .topLeft:
                        arr.insert(.layerMinXMinYCorner)
                    case .topRight:
                        arr.insert(.layerMaxXMinYCorner)
                    case .bottomLeft:
                        arr.insert(.layerMinXMaxYCorner)
                    case .bottomRight:
                        arr.insert(.layerMaxXMaxYCorner)
                    case .allCorners:
                        arr.insert(.layerMinXMinYCorner)
                        arr.insert(.layerMaxXMinYCorner)
                        arr.insert(.layerMinXMaxYCorner)
                        arr.insert(.layerMaxXMaxYCorner)
                    default: break
                    }
                }
            }
            self.layer.maskedCorners = arr
        } else {
            self.roundCornersBezierPath(corners: corners, radius: radius)
        }
    }
    
    private func roundCornersBezierPath(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
    }
    
}