我想在 Swift -3 中为视图设置不同的角半径，我可以将每个角的半径设置为与以下帖子中提到的值相同的值，how to set cornerRadius for only top-left and top-right corner of a UIView?
有没有办法可以按以下格式设置圆角半径？ 左上角半径：18 右上方半径：18 右下角半径：3 半径左下角：18
【问题讨论】：
标签： ios swift3 cornerradius
在 iOS 11 之后执行此操作的最佳方式，这样看起来更流畅。
func roundCorners(_ corners: UIRectCorner, radius: CGFloat) {
clipsToBounds = true
layer.cornerRadius = radius
layer.maskedCorners = CACornerMask(rawValue: corners.rawValue)
}
【讨论】：
基于@Kirill Dobryakov 的略微改进和简化的答案。曲线可能会留下非常小的但明显的不规则性，当您查看它并且您知道它不是理想的圆形时（尝试例如查看边 40 和半径 20）。我不知道这怎么可能，但无论如何，最可靠的方法是使用弧线来制作理想的圆角，以及为您提供@IBDesigneable 组件：
extension UIBezierPath {
convenience init(shouldRoundRect rect: CGRect, topLeftRadius: CGFloat, topRightRadius: CGFloat, bottomLeftRadius: CGFloat, bottomRightRadius: CGFloat){
self.init()
let path = CGMutablePath()
let topLeft = rect.origin
let topRight = CGPoint(x: rect.maxX, y: rect.minY)
let bottomRight = CGPoint(x: rect.maxX, y: rect.maxY)
let bottomLeft = CGPoint(x: rect.minX, y: rect.maxY)
if topLeftRadius != 0 {
path.move(to: CGPoint(x: topLeft.x + topLeftRadius, y: topLeft.y))
} else {
path.move(to: topLeft)
}
if topRightRadius != 0 {
path.addLine(to: CGPoint(x: topRight.x - topRightRadius, y: topRight.y))
path.addArc(tangent1End: topRight, tangent2End: CGPoint(x: topRight.x, y: topRight.y + topRightRadius), radius: topRightRadius)
}
else {
path.addLine(to: topRight)
}
if bottomRightRadius != 0 {
path.addLine(to: CGPoint(x: bottomRight.x, y: bottomRight.y - bottomRightRadius))
path.addArc(tangent1End: bottomRight, tangent2End: CGPoint(x: bottomRight.x - bottomRightRadius, y: bottomRight.y), radius: bottomRightRadius)
}
else {
path.addLine(to: bottomRight)
}
if bottomLeftRadius != 0 {
path.addLine(to: CGPoint(x: bottomLeft.x + bottomLeftRadius, y: bottomLeft.y))
path.addArc(tangent1End: bottomLeft, tangent2End: CGPoint(x: bottomLeft.x, y: bottomLeft.y - bottomLeftRadius), radius: bottomLeftRadius)
}
else {
path.addLine(to: bottomLeft)
}
if topLeftRadius != 0 {
path.addLine(to: CGPoint(x: topLeft.x, y: topLeft.y + topLeftRadius))
path.addArc(tangent1End: topLeft, tangent2End: CGPoint(x: topLeft.x + topLeftRadius, y: topLeft.y), radius: topLeftRadius)
}
else {
path.addLine(to: topLeft)
}
path.closeSubpath()
cgPath = path
}
}
@IBDesignable
open class VariableCornerRadiusView: UIView {
private func applyRadiusMaskFor() {
let path = UIBezierPath(shouldRoundRect: bounds, topLeftRadius: topLeftRadius, topRightRadius: topRightRadius, bottomLeftRadius: bottomLeftRadius, bottomRightRadius: bottomRightRadius)
let shape = CAShapeLayer()
shape.path = path.cgPath
layer.mask = shape
}
@IBInspectable
open var topLeftRadius: CGFloat = 0 {
didSet { setNeedsLayout() }
}
@IBInspectable
open var topRightRadius: CGFloat = 0 {
didSet { setNeedsLayout() }
}
@IBInspectable
open var bottomLeftRadius: CGFloat = 0 {
didSet { setNeedsLayout() }
}
@IBInspectable
open var bottomRightRadius: CGFloat = 0 {
didSet { setNeedsLayout() }
}
override open func layoutSubviews() {
super.layoutSubviews()
applyRadiusMaskFor()
}
}
【讨论】：
UIViewController 执行此操作的，所以我覆盖了viewDidLayoutSubviews 并再次调用它。修复了问题
layoutSubviews()，它应该可以完成这项工作。可能是您的具体情况。
是否要为每个角添加唯一角值？
之后您要添加边框吗？
我有一个解决方案，如下所示：
首先，添加我做的UIBezierPath扩展：
extension UIBezierPath {
convenience init(shouldRoundRect rect: CGRect, topLeftRadius: CGSize = .zero, topRightRadius: CGSize = .zero, bottomLeftRadius: CGSize = .zero, bottomRightRadius: CGSize = .zero){
self.init()
let path = CGMutablePath()
let topLeft = rect.origin
let topRight = CGPoint(x: rect.maxX, y: rect.minY)
let bottomRight = CGPoint(x: rect.maxX, y: rect.maxY)
let bottomLeft = CGPoint(x: rect.minX, y: rect.maxY)
if topLeftRadius != .zero{
path.move(to: CGPoint(x: topLeft.x+topLeftRadius.width, y: topLeft.y))
} else {
path.move(to: CGPoint(x: topLeft.x, y: topLeft.y))
}
if topRightRadius != .zero{
path.addLine(to: CGPoint(x: topRight.x-topRightRadius.width, y: topRight.y))
path.addCurve(to: CGPoint(x: topRight.x, y: topRight.y+topRightRadius.height), control1: CGPoint(x: topRight.x, y: topRight.y), control2:CGPoint(x: topRight.x, y: topRight.y+topRightRadius.height))
} else {
path.addLine(to: CGPoint(x: topRight.x, y: topRight.y))
}
if bottomRightRadius != .zero{
path.addLine(to: CGPoint(x: bottomRight.x, y: bottomRight.y-bottomRightRadius.height))
path.addCurve(to: CGPoint(x: bottomRight.x-bottomRightRadius.width, y: bottomRight.y), control1: CGPoint(x: bottomRight.x, y: bottomRight.y), control2: CGPoint(x: bottomRight.x-bottomRightRadius.width, y: bottomRight.y))
} else {
path.addLine(to: CGPoint(x: bottomRight.x, y: bottomRight.y))
}
if bottomLeftRadius != .zero{
path.addLine(to: CGPoint(x: bottomLeft.x+bottomLeftRadius.width, y: bottomLeft.y))
path.addCurve(to: CGPoint(x: bottomLeft.x, y: bottomLeft.y-bottomLeftRadius.height), control1: CGPoint(x: bottomLeft.x, y: bottomLeft.y), control2: CGPoint(x: bottomLeft.x, y: bottomLeft.y-bottomLeftRadius.height))
} else {
path.addLine(to: CGPoint(x: bottomLeft.x, y: bottomLeft.y))
}
if topLeftRadius != .zero{
path.addLine(to: CGPoint(x: topLeft.x, y: topLeft.y+topLeftRadius.height))
path.addCurve(to: CGPoint(x: topLeft.x+topLeftRadius.width, y: topLeft.y) , control1: CGPoint(x: topLeft.x, y: topLeft.y) , control2: CGPoint(x: topLeft.x+topLeftRadius.width, y: topLeft.y))
} else {
path.addLine(to: CGPoint(x: topLeft.x, y: topLeft.y))
}
path.closeSubpath()
cgPath = path
}
}
那么，添加这个UIView扩展：
extension UIView{
func roundCorners(topLeft: CGFloat = 0, topRight: CGFloat = 0, bottomLeft: CGFloat = 0, bottomRight: CGFloat = 0) {//(topLeft: CGFloat, topRight: CGFloat, bottomLeft: CGFloat, bottomRight: CGFloat) {
let topLeftRadius = CGSize(width: topLeft, height: topLeft)
let topRightRadius = CGSize(width: topRight, height: topRight)
let bottomLeftRadius = CGSize(width: bottomLeft, height: bottomLeft)
let bottomRightRadius = CGSize(width: bottomRight, height: bottomRight)
let maskPath = UIBezierPath(shouldRoundRect: bounds, topLeftRadius: topLeftRadius, topRightRadius: topRightRadius, bottomLeftRadius: bottomLeftRadius, bottomRightRadius: bottomRightRadius)
let shape = CAShapeLayer()
shape.path = maskPath.cgPath
layer.mask = shape
}
}
最后，调用方法
myView.roundCorners(topLeft: 10, topRight: 20, bottomLeft: 30, bottomRight: 40)
并添加边框。显然，layer.borderRadius 不能正常工作，所以使用CAShapeLayer 和之前创建的路径创建一个边框。
let borderLayer = CAShapeLayer()
borderLayer.path = (myView.layer.mask! as! CAShapeLayer).path! // Reuse the Bezier path
borderLayer.strokeColor = UIColor.red.cgColor
borderLayer.fillColor = UIColor.clear.cgColor
borderLayer.lineWidth = 5
borderLayer.frame = myView.bounds
myView.layer.addSublayer(borderLayer)
瞧！
【讨论】：
path.addLine(to: CGPoint(x: topLeft.x, y: topLeft.y)) if 可以是path.addLine(to: topLeft) 和许多类似的行。
您可以将默认的layer.cornerRadius 设置为最小值，然后将图层蒙版的边框设置为较大的值。
let demoView = UIView(frame: CGRect(x: 100, y: 200, width: 100, height: 100))
demoView.backgroundColor = UIColor.red
demoView.layer.cornerRadius = 3.0
let maskPath = UIBezierPath(roundedRect: demoView.bounds,
byRoundingCorners: [.topLeft, .topRight, .bottomLeft],
cornerRadii: CGSize(width: 18.0, height: 0.0))
let maskLayer = CAShapeLayer()
maskLayer.path = maskPath.cgPath
demoView.layer.mask = maskLayer
view.addSubview(demoView)
【讨论】：