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
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。
其他回答
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)
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。
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
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。
// Create the path (with only the top-left corner rounded)
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds
byRoundingCorners:(UIRectCornerBottomLeft | UIRectCornerBottomRight)
cornerRadii:CGSizeMake(7.0, 7.0)];
// Create the shape layer and set its path
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = cell.stripBlackImnageView.bounds;
maskLayer.path = maskPath.CGPath;
// Set the newly created shapelayer as the mask for the image view's layer
view.layer.mask = maskLayer;
