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

最后,在iOS11中有CACornerMask ! 使用CACornerMask可以很容易地完成:

let view = UIView()
view.clipsToBounds = true
view.layer.cornerRadius = 10
view.layer.maskedCorners = [.layerMaxXMinYCorner, .layerMinXMinYCorner] // Top right corner, Top left corner respectively

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)
    }
    
}

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>

下面是一个实现的简短方法:

- (void)viewDidLoad {
    [super viewDidLoad];
    UIButton *openInMaps = [UIButton new];
    [openInMaps setFrame:CGRectMake(15, 135, 114, 70)];
    openInMaps = (UIButton *)[self roundCornersOnView:openInMaps onTopLeft:NO topRight:NO bottomLeft:YES bottomRight:NO radius:5.0];
}

- (UIView *)roundCornersOnView:(UIView *)view onTopLeft:(BOOL)tl topRight:(BOOL)tr bottomLeft:(BOOL)bl bottomRight:(BOOL)br radius:(float)radius {

    if (tl || tr || bl || br) {
        UIRectCorner corner = 0;
        if (tl) {corner = corner | UIRectCornerTopLeft;}
        if (tr) {corner = corner | UIRectCornerTopRight;}
        if (bl) {corner = corner | UIRectCornerBottomLeft;}
        if (br) {corner = corner | UIRectCornerBottomRight;}

        UIView *roundedView = view;
        UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:roundedView.bounds byRoundingCorners:corner cornerRadii:CGSizeMake(radius, radius)];
        CAShapeLayer *maskLayer = [CAShapeLayer layer];
        maskLayer.frame = roundedView.bounds;
        maskLayer.path = maskPath.CGPath;
        roundedView.layer.mask = maskLayer;
        return roundedView;
    }
    return view;
}

这是最简单的答案:

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