有没有一种方法可以仅为UIView的左上角和右上角设置cornerRadius？
我尝试了以下方法，但最终导致无法看到视图。
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;
我不确定为什么您的解决方案没有起作用，但是以下代码对我有效。创建一个贝塞尔掩码并将其应用于您的视图。在下面的代码中，我将_backgroundView的底部圆角半径设置为3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;
一些改进的 Swift 2.0 版本:
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
这里有一个关于Swift扩展的链接
viewDidLoad 方法里，但当我将其移动到 viewDidAppear 时，问题得以解决。 - Luchopath.CGPath 应该是 path.cgPath。 - RobviewToRound.layoutIfNeeded()。谢谢。 - Nazmul Hasan最后… 在iOS11中有CACornerMask！
使用CACornerMask非常容易实现：
let view = UIView()
view.clipsToBounds = true
view.layer.cornerRadius = 10
view.layer.maskedCorners = [.layerMaxXMinYCorner, .layerMinXMinYCorner] // Top right corner, Top left corner respectively
请注意，如果您的UIView子类附有布局约束，则必须按如下方式刷新：
override func layoutSubviews() {
super.layoutSubviews()
roundCorners(corners: [.topLeft, .topRight], radius: 3.0)
}
如果您不这样做，它就不会出现。
而且要使用扩展来实现圆角：
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
}
}
额外的视图控制器案例: 无论您是不想子类化视图还是不能子类化视图，您仍然可以使视图变圆。通过覆盖viewWillLayoutSubviews()函数来完成它,如下：
class MyVC: UIViewController {
/// The view to round the top-left and top-right hand corners
let theView: UIView = {
let v = UIView(frame: CGRect(x: 10, y: 10, width: 200, height: 200))
v.backgroundColor = .red
return v
}()
override func loadView() {
super.loadView()
view.addSubview(theView)
}
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
// Call the roundCorners() func right there.
theView.roundCorners(corners: [.topLeft, .topRight], radius: 30)
}
}
这里是@JohnnyRockex答案的Swift版本。
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)
如果您正在使用自动布局，则需要子类化您的UIView并在视图的layoutSubviews方法中调用roundCorners以获得最佳效果。
class View: UIView {
override func layoutSubviews() {
super.layoutSubviews()
self.roundCorners([.topLeft, .bottomLeft], radius: 10)
}
}
view.roundCorners([.TopLeft , .BottomLeft], radius: 10)表示将视图view的左上和左下角设置为圆角，圆角半径为10。 - fahrulazmi.layoutIfNeeded()方法，然后再调用此方法。 - zgjie这里有Swift代码示例: https://dev59.com/I10b5IYBdhLWcg3wGN0s#35621736
不能直接设置。您需要:
CAShapeLayerpath 设置为基于 view.bounds 的 CGPathRef，但仅具有两个圆角（可能使用 +[UIBezierPath bezierPathWithRoundedRect:byRoundingCorners:cornerRadii:] 实现）view.layer.mask 设置为该 CAShapeLayer这里有一个简短的实现方法：
- (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;
}
它也可以在Swift 5.x上工作，按照我的完整答案操作。
在Swift 4.1和Xcode 9.4.1中：
在中，这一行就足够了：
detailsSubView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]//Set your view here
查看完整代码：
//In viewDidLoad
if #available(iOS 11.0, *) {
detailsSubView.clipsToBounds = false
detailsSubView.layer.cornerRadius = 10
detailsSubView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
} else {
//For lower versions
}
但对于较低版本
let rectShape = CAShapeLayer()
rectShape.bounds = detailsSubView.frame
rectShape.position = detailsSubView.center
rectShape.path = UIBezierPath(roundedRect: detailsSubView.bounds, byRoundingCorners: [.topLeft , .topRight], cornerRadii: CGSize(width: 20, height: 20)).cgPath
detailsSubView.layer.mask = rectShape
完整的代码如下。
if #available(iOS 11.0, *) {
detailsSubView.clipsToBounds = false
detailsSubView.layer.cornerRadius = 10
detailsSubView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
} else {
let rectShape = CAShapeLayer()
rectShape.bounds = detailsSubView.frame
rectShape.position = detailsSubView.center
rectShape.path = UIBezierPath(roundedRect: detailsSubView.bounds, byRoundingCorners: [.topLeft , .topRight], cornerRadii: CGSize(width: 20, height: 20)).cgPath
detailsSubView.layer.mask = rectShape
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if #available(iOS 11.0, *) {
detailsSubView.clipsToBounds = false
detailsSubView.layer.cornerRadius = 10
detailsSubView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
} else {
let rectShape = CAShapeLayer()
rectShape.bounds = detailsSubView.frame
rectShape.position = detailsSubView.center
rectShape.path = UIBezierPath(roundedRect: detailsSubView.bounds, byRoundingCorners: [.topLeft , .topRight], cornerRadii: CGSize(width: 20, height: 20)).cgPath
detailsSubView.layer.mask = rectShape
}
}
detailsSubView.clipsToBounds = false 应该改为 true，对吗？ - byJeevan有一种非常简单的方法来完成它。我在这里找到了它。
view.clipsToBounds = true
view.layer.cornerRadius = 24
view.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
它使用视图的CALayer上的库存cornerRadius属性。您只需要定义角落。layerMinXMinYCorner是左上角，layerMaxXMinYCorner是右上角。
yourView.layer.cornerRadius = 8
yourView.layer.masksToBounds = true
yourView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
用一行代码轻松实现Swift 4和Swift 5
用法：
//MARK:- Corner Radius of only two side of UIViews
self.roundCorners(view: yourview, corners: [.bottomLeft, .topRight], radius: 12.0)
功能：
//MARK:- Corner Radius of only two side of UIViews
func roundCorners(view :UIView, corners: UIRectCorner, radius: CGFloat){
let path = UIBezierPath(roundedRect: view.bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
let mask = CAShapeLayer()
mask.path = path.cgPath
view.layer.mask = mask
}
在Objective-C中
用法：
[self.verticalSeparatorView roundCorners:UIRectCornerTopLeft | UIRectCornerTopRight radius:10.0];
该函数用于一个类别中（仅应用于一个角）：
-(void)roundCorners: (UIRectCorner) corners radius:(CGFloat)radius {
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:self.bounds byRoundingCorners:corners cornerRadii:CGSizeMake(radius, radius)];
CAShapeLayer *mask = [[CAShapeLayer alloc] init];
mask.path = path.CGPath;
self.layer.mask = mask;
}
view.bounds，而不是frame；(2)图层应该是一个CAShapeLayer，而不是CALayer；(3)设置图层的path，而不是shadowPath。 - Kurt Revis