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

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
}()

其他回答

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)
    }
    
}

使用这个扩展,它将涵盖一切。

extension UIView {

   func roundTopCorners(radius: CGFloat = 10) {
    
       self.clipsToBounds = true
       self.layer.cornerRadius = radius
       if #available(iOS 11.0, *) {
           self.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
       } else {
           self.roundCorners(corners: [.topLeft, .topRight], radius: radius)
       }
   }

   func roundBottomCorners(radius: CGFloat = 10) {
    
       self.clipsToBounds = true
       self.layer.cornerRadius = radius
       if #available(iOS 11.0, *) {
           self.layer.maskedCorners = [.layerMinXMaxYCorner, .layerMaxXMaxYCorner]
       } else {
           self.roundCorners(corners: [.bottomLeft, .bottomRight], radius: radius)
       }
   }

   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
    }
}

然后像这样使用它:-

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
            
    self.yourView.roundTopCorners()
}

注意:-我建议你不要把这段代码放在viewDidLayoutSubviews()中,因为每当视图更新时,你都会在里面得到调用。所以使用viewDidAppear(),它会像一个咒语一样工作。

Emma: . topright和。bottom right对你不起作用,可能是因为视图调用。roundCorners是在最终视图边界计算之前完成的。注意,贝塞尔路径在被调用时起源于视图边界。例如,如果自动布局将缩小视图,右侧的圆角可能在视图之外。 尝试在viewDidLayoutSubviews中调用它,其中视图的边界是final。

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
        }
    }

}

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>