每个角的角半径不同

Question

我想在 iOS 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相同的值如何仅为 UIView 的左上角和右上角设置角半径？

有没有一种方法可以按以下格式设置角半径？

左上角半径：18
右上半径：18
右下角半径：3
左下角半径：18

Answer 1

你想为每个角添加独特的角值吗？

之后要添加边框吗？

我有一个解决方案如下所示：

首先，添加一个

UIBezierPath

我做的扩展：

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
    }
}

然后，添加这个

UIView

扩展名：

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 无法正常工作，因此使用

CAShapeLayer

和先前创建的路径创建边框。

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！

Answer 2

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)

Answer 3

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（例如尝试查看 40 边和 20 半径）。我不知道这是怎么可能的，但无论如何，最可靠的方法是使用圆弧来制作理想的圆角，并为您提供

@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()
    }
}

Answer 4

在 iOS 11 开始的 Swift 中：

view.layer.cornerRadius = 50
view.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMinYCorner]

Answer 5

在 iOS 11 之后最好的方法，那样看起来更流畅。

 func roundCorners(_ corners: UIRectCorner, radius: CGFloat) {
        clipsToBounds = true
        layer.cornerRadius = radius
        layer.maskedCorners = CACornerMask(rawValue: corners.rawValue)
  }

原始答案：https://stackoverflow.com/a/50289822/4206186