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
Stephane回答的另一个版本。
import UIKit
class RoundCornerView: UIView {
var corners : UIRectCorner = [.topLeft,.topRight,.bottomLeft,.bottomRight]
var roundCornerRadius : CGFloat = 0.0
override func layoutSubviews() {
super.layoutSubviews()
if corners.rawValue > 0 && roundCornerRadius > 0.0 {
self.roundCorners(corners: corners, radius: roundCornerRadius)
}
}
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
}
}
其他回答
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。
斯威夫特4
extension UIView {
func roundTop(radius:CGFloat = 5){
self.clipsToBounds = true
self.layer.cornerRadius = radius
if #available(iOS 11.0, *) {
self.layer.maskedCorners = [.layerMaxXMinYCorner, .layerMinXMinYCorner]
} else {
// Fallback on earlier versions
}
}
func roundBottom(radius:CGFloat = 5){
self.clipsToBounds = true
self.layer.cornerRadius = radius
if #available(iOS 11.0, *) {
self.layer.maskedCorners = [.layerMaxXMaxYCorner, .layerMinXMaxYCorner]
} else {
// Fallback on earlier versions
}
}
}
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
}
}
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。
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
