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

    // 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;

其他回答

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

一个可爱的扩展重用尤努斯Nedim Mehel解决方案

斯威夫特2.3

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
} }

使用

let view = UIView()
view.roundCornersWithLayerMask(10,[.TopLeft,.TopRight])

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;
}

有一个超级简单的方法。我在这里找到的。

view.clipsToBounds = true
view.layer.cornerRadius = 24
view.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]

它在视图的CALayer上使用stock cornerRadius属性。你只需要定义这些角。layerMinXMinYCorner是左上layerMaxXMinYCorner是右上。

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;