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 4.1和Xcode 9.4.1中
在iOS 11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
}
但是对于低版本
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
完整的代码是。
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
}
如果你在故事板中使用AutoResizing，请在viewDidLayoutSubviews()中编写以下代码。
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
}
}
其他回答
注意，如果你有布局约束附加到它，你必须在你的UIView子类中按如下方式刷新它:
override func layoutSubviews() {
super.layoutSubviews()
roundCorners(corners: [.topLeft, .topRight], radius: 3.0)
}
如果你不这样做，它就不会出现。
和圆角，使用扩展:
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
}
}
附加的视图控制器情况:无论你不能或不想子类化一个视图，你仍然可以舍入一个视图。通过覆盖viewWillLayoutSubviews()函数，从它的视图控制器中完成，如下所示:
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)
}
}
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)
iOS 11, Swift 4 你可以试试这段代码:
if #available(iOS 11.0, *) {
element.clipsToBounds = true
element.layer.cornerRadius = CORNER_RADIUS
element.layer.maskedCorners = [.layerMaxXMaxYCorner]
} else {
// Fallback on earlier versions
}
你可以在表格视图单元格中使用这个。
如果你正在寻找一个界面构建器的唯一解决方案，有一个适用于iOS 11或更高版本。在这里可以看到我的答案:https://stackoverflow.com/a/58626264
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])
