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

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)
    }
}

其他回答

简单的扩展

extension UIView {
    func roundCorners(corners: UIRectCorner, radius: CGFloat) {
        if #available(iOS 11, *) {
            self.clipsToBounds = true
            self.layer.cornerRadius = radius
            var masked = CACornerMask()
            if corners.contains(.topLeft) { masked.insert(.layerMinXMinYCorner) }
            if corners.contains(.topRight) { masked.insert(.layerMaxXMinYCorner) }
            if corners.contains(.bottomLeft) { masked.insert(.layerMinXMaxYCorner) }
            if corners.contains(.bottomRight) { masked.insert(.layerMaxXMaxYCorner) }
            self.layer.maskedCorners = masked
        }
        else {
            let path = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
            let mask = CAShapeLayer()
            mask.path = path.cgPath
            layer.mask = mask
        }
    }
}

用法:

view.roundCorners(corners: [.bottomLeft, .bottomRight], radius: 12)

我不知道为什么你的解决方案没有工作,但下面的代码是为我工作。创建一个贝塞尔蒙版,并将其应用到您的视图。在下面的代码中,我将_backgroundView的底角圆角化为3个像素。self是一个自定义的UITableViewCell:

UIBezierPath *maskPath = [UIBezierPath
    bezierPathWithRoundedRect:self.backgroundImageView.bounds
    byRoundingCorners:(UIRectCornerBottomLeft | UIRectCornerBottomRight)
    cornerRadii:CGSizeMake(20, 20)
];

CAShapeLayer *maskLayer = [CAShapeLayer layer];

maskLayer.frame = self.bounds;
maskLayer.path = maskPath.CGPath;

self.backgroundImageView.layer.mask = maskLayer;

Swift 2.0版本与一些改进:

let path = UIBezierPath(roundedRect:viewToRound.bounds, byRoundingCorners:[.TopRight, .BottomLeft], cornerRadii: CGSizeMake(20, 20))
let maskLayer = CAShapeLayer()

maskLayer.path = path.CGPath
viewToRound.layer.mask = maskLayer

Swift 3.0版本:

let path = UIBezierPath(roundedRect:viewToRound.bounds,
                        byRoundingCorners:[.topRight, .bottomLeft],
                        cornerRadii: CGSize(width: 20, height:  20))

let maskLayer = CAShapeLayer()

maskLayer.path = path.cgPath
viewToRound.layer.mask = maskLayer

这里的快速扩展

一种编程的方法是创建一个UIView在UIView顶部有圆角的部分。或者你可以把顶部藏在什么东西下面。

我的解决方案圆角的UIView和uitextfields在swift是使用

.layer.cornerRadius

and

layer.maskedCorners

实际的UIView或UITextFields。

例子:

fileprivate func inputTextFieldStyle() {
        inputTextField.layer.masksToBounds = true
        inputTextField.layer.borderWidth = 1
        inputTextField.layer.cornerRadius = 25
        inputTextField.layer.maskedCorners = [.layerMaxXMaxYCorner,.layerMaxXMinYCorner]
        inputTextField.layer.borderColor = UIColor.white.cgColor
    }

通过使用

layerMaxXMaxYCorner。

and

layerMaxXMinYCorner。

,我可以指定UITextField的右上角和右下角是四舍五入的。

你可以在这里看到结果:

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)
    }
}