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
对于 SwiftUI
我找到了这些解决方案，你可以在这里查看https://stackoverflow.com/a/56763282/3716103
我强烈推荐第一个
选项1:使用Path + GeometryReader
(更多关于GeometryReader的信息:https://swiftui-lab.com/geometryreader-to-the-rescue/)
struct ContentView : View {
var body: some View {
Text("Hello World!")
.foregroundColor(.white)
.font(.largeTitle)
.padding(20)
.background(RoundedCorners(color: .blue, tl: 0, tr: 30, bl: 30, br: 0))
}
}
RoundedCorners
struct RoundedCorners: View {
var color: Color = .white
var tl: CGFloat = 0.0
var tr: CGFloat = 0.0
var bl: CGFloat = 0.0
var br: CGFloat = 0.0
var body: some View {
GeometryReader { geometry in
Path { path in
let w = geometry.size.width
let h = geometry.size.height
// Make sure we do not exceed the size of the rectangle
let tr = min(min(self.tr, h/2), w/2)
let tl = min(min(self.tl, h/2), w/2)
let bl = min(min(self.bl, h/2), w/2)
let br = min(min(self.br, h/2), w/2)
path.move(to: CGPoint(x: w / 2.0, y: 0))
path.addLine(to: CGPoint(x: w - tr, y: 0))
path.addArc(center: CGPoint(x: w - tr, y: tr), radius: tr, startAngle: Angle(degrees: -90), endAngle: Angle(degrees: 0), clockwise: false)
path.addLine(to: CGPoint(x: w, y: h - be))
path.addArc(center: CGPoint(x: w - br, y: h - br), radius: br, startAngle: Angle(degrees: 0), endAngle: Angle(degrees: 90), clockwise: false)
path.addLine(to: CGPoint(x: bl, y: h))
path.addArc(center: CGPoint(x: bl, y: h - bl), radius: bl, startAngle: Angle(degrees: 90), endAngle: Angle(degrees: 180), clockwise: false)
path.addLine(to: CGPoint(x: 0, y: tl))
path.addArc(center: CGPoint(x: tl, y: tl), radius: tl, startAngle: Angle(degrees: 180), endAngle: Angle(degrees: 270), clockwise: false)
}
.fill(self.color)
}
}
}
RoundedCorners_Previews
struct RoundedCorners_Previews: PreviewProvider {
static var previews: some View {
RoundedCorners(color: .pink, tl: 40, tr: 40, bl: 40, br: 40)
}
}
其他回答
使用这个扩展，它将涵盖一切。
extension UIView {
func roundTopCorners(radius: CGFloat = 10) {
self.clipsToBounds = true
self.layer.cornerRadius = radius
if #available(iOS 11.0, *) {
self.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
} else {
self.roundCorners(corners: [.topLeft, .topRight], radius: radius)
}
}
func roundBottomCorners(radius: CGFloat = 10) {
self.clipsToBounds = true
self.layer.cornerRadius = radius
if #available(iOS 11.0, *) {
self.layer.maskedCorners = [.layerMinXMaxYCorner, .layerMaxXMaxYCorner]
} else {
self.roundCorners(corners: [.bottomLeft, .bottomRight], radius: radius)
}
}
private 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
}
}
然后像这样使用它:-
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
self.yourView.roundTopCorners()
}
注意:-我建议你不要把这段代码放在viewDidLayoutSubviews()中，因为每当视图更新时，你都会在里面得到调用。所以使用viewDidAppear()，它会像一个咒语一样工作。
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。
这是最简单的答案:
yourView.layer.cornerRadius = 8
yourView.layer.masksToBounds = true
yourView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]
我不知道为什么你的解决方案没有工作，但下面的代码是为我工作。创建一个贝塞尔蒙版，并将其应用到您的视图。在下面的代码中，我将_backgroundView的底角圆角化为3个像素。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;
Swift 2.0版本与一些改进:
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
这里的快速扩展
