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
试试这段代码，
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds byRoundingCorners:( UIRectCornerTopLeft | UIRectCornerTopRight) cornerRadii:CGSizeMake(5.0, 5.0)];
CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
maskLayer.frame = self.view.bounds;
maskLayer.path = maskPath.CGPath;
view.layer.mask = maskLayer;
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)
}
}
所有已经给出的答案都是非常好的和有效的(特别是尤努斯使用蒙版属性的想法)。
然而，我需要一些更复杂的东西，因为我的层可以经常改变大小，这意味着我需要每次都调用掩蔽逻辑，这有点烦人。
我使用了swift扩展和计算属性来构建一个真正的cornerRadii属性，它负责在图层布局时自动更新蒙版。
这是使用Peter Steinberg伟大的Aspects库实现的。
完整代码在这里:
extension CALayer {
// This will hold the keys for the runtime property associations
private struct AssociationKey {
static var CornerRect:Int8 = 1 // for the UIRectCorner argument
static var CornerRadius:Int8 = 2 // for the radius argument
}
// new computed property on CALayer
// You send the corners you want to round (ex. [.TopLeft, .BottomLeft])
// and the radius at which you want the corners to be round
var cornerRadii:(corners: UIRectCorner, radius:CGFloat) {
get {
let number = objc_getAssociatedObject(self, &AssociationKey.CornerRect) as? NSNumber ?? 0
let radius = objc_getAssociatedObject(self, &AssociationKey.CornerRadius) as? NSNumber ?? 0
return (corners: UIRectCorner(rawValue: number.unsignedLongValue), radius: CGFloat(radius.floatValue))
}
set (v) {
let radius = v.radius
let closure:((Void)->Void) = {
let path = UIBezierPath(roundedRect: self.bounds, byRoundingCorners: v.corners, cornerRadii: CGSize(width: radius, height: radius))
let mask = CAShapeLayer()
mask.path = path.CGPath
self.mask = mask
}
let block: @convention(block) Void -> Void = closure
let objectBlock = unsafeBitCast(block, AnyObject.self)
objc_setAssociatedObject(self, &AssociationKey.CornerRect, NSNumber(unsignedLong: v.corners.rawValue), .OBJC_ASSOCIATION_RETAIN)
objc_setAssociatedObject(self, &AssociationKey.CornerRadius, NSNumber(float: Float(v.radius)), .OBJC_ASSOCIATION_RETAIN)
do { try aspect_hookSelector("layoutSublayers", withOptions: .PositionAfter, usingBlock: objectBlock) }
catch _ { }
}
}
}
我写了一篇简单的博客来解释这一点。
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
}
}
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。
试试这段代码，
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds byRoundingCorners:( UIRectCornerTopLeft | UIRectCornerTopRight) cornerRadii:CGSizeMake(5.0, 5.0)];
CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
maskLayer.frame = self.view.bounds;
maskLayer.path = maskPath.CGPath;
view.layer.mask = maskLayer;
