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
一种编程的方法是创建一个UIView在UIView顶部有圆角的部分。或者你可以把顶部藏在什么东西下面。
其他回答
最简单的方法是用圆角层做一个蒙版。
CALayer *maskLayer = [CALayer layer];
maskLayer.frame = CGRectMake(0,0,maskWidth ,maskHeight);
maskLayer.contents = (__bridge id)[[UIImage imageNamed:@"maskImageWithRoundedCorners.png"] CGImage];
aUIView.layer.mask = maskLayer;
别忘了:
#import <QuartzCore/QuartzCore.h>
这是如何在c#中使用Xamarin为按钮的每个角落设置角半径:
var maskPath = UIBezierPath.FromRoundedRect(MyButton.Bounds, UIRectCorner.BottomLeft | UIRectCorner.BottomRight,
new CGSize(10.0, 10.0));
var maskLayer = new CAShapeLayer
{
Frame = MyButton.Bounds,
Path = maskPath.CGPath
};
MyButton.Layer.Mask = maskLayer;
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
}
}
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
}
}
}
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。
