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

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
}()

下面是@JohnnyRockex的Swift版本的回答

extension UIView {

    func roundCorners(_ corners: UIRectCorner, radius: CGFloat) {
         let path = UIBezierPath(roundedRect: self.bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
         let mask = CAShapeLayer()
         mask.path = path.cgPath
         self.layer.mask = mask
    }

}

view.roundCorners([.topLeft, .bottomRight], radius: 10)

Note

如果你正在使用自动布局,你需要子类化你的UIView,并在视图的layoutSubviews中调用roundCorners以获得最佳效果。

class View: UIView {
    override func layoutSubviews() {
        super.layoutSubviews()

        self.roundCorners([.topLeft, .bottomLeft], radius: 10)
    }
}

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;
    // 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;

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
        }
    }

}