Question

我想为Swift -3中的视图设置不同的角半径，我可以将每个角的半径设置为相同的值，如下面帖子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转角半径？半径左上：18 半径右上：18 半径右下：3 半径左下：18

Answer 1

您可以将默认值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 2

是否要为每个角添加唯一角值？

之后是否要添加边框？

我有解决方法（looks like this）！

首先，添加我创建的UIBezierPath扩展名：

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，添加此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，因此请使用CAShapeLayer和先前创建的路径来创建边框。

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)

Voila！

Answer 3

基于@Kirill Dobryakov的回答略有改进和简化。当您查看曲线时，曲线可能会留下很小但明显的不规则性，并且您知道它并不是理想的圆形（例如，查看40号边和20号半径）。我什至不知道这怎么可能，但是无论如何，最可靠的方法是使用能形成理想圆角的圆弧，并且还为您提供@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之后执行此操作的最佳方法，它看起来更流畅。

 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

不同的cornerRadius为每个角落Swift 3 - iOS

4 个答案: