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
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。
其他回答
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])
以下是Swift 5的最佳方法:
import UIKit
extension UIView {
func roundCorners(radius: CGFloat = 10, corners: UIRectCorner = .allCorners) {
self.clipsToBounds = true
self.layer.cornerRadius = radius
if #available(iOS 11.0, *) {
var arr: CACornerMask = []
let allCorners: [UIRectCorner] = [.topLeft, .topRight, .bottomLeft, .bottomRight, .allCorners]
for corn in allCorners {
if(corners.contains(corn)){
switch corn {
case .topLeft:
arr.insert(.layerMinXMinYCorner)
case .topRight:
arr.insert(.layerMaxXMinYCorner)
case .bottomLeft:
arr.insert(.layerMinXMaxYCorner)
case .bottomRight:
arr.insert(.layerMaxXMaxYCorner)
case .allCorners:
arr.insert(.layerMinXMinYCorner)
arr.insert(.layerMaxXMinYCorner)
arr.insert(.layerMinXMaxYCorner)
arr.insert(.layerMaxXMaxYCorner)
default: break
}
}
}
self.layer.maskedCorners = arr
} else {
self.roundCornersBezierPath(corners: corners, radius: radius)
}
}
private func roundCornersBezierPath(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
}
}
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
Emma: . topright和。bottom right对你不起作用，可能是因为视图调用。roundCorners是在最终视图边界计算之前完成的。注意，贝塞尔路径在被调用时起源于视图边界。例如，如果自动布局将缩小视图，右侧的圆角可能在视图之外。 尝试在viewDidLayoutSubviews中调用它，其中视图的边界是final。
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)
