如何更改 CAShapeLayer 内的区域？

Question

我创建了带有自定义 UIBezierPath 和填充颜色的 CAShapeLayer。如何更改路径内的区域？使其成为 bigger/lower.

    private var path = UIBezierPath()
    private var shapeLayer = CAShapeLayer()

    override public func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first as UITouch? {
            let touchPoint = touch.location(in: self)
            path.move(to: touchPoint)
        }
    }

    override public func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first as UITouch? {
            let touchPoint = touch.location(in: self)
            path.addLine(to: touchPoint)
            shapeLayer.path = path.cgPath
            shapeLayer.strokeColor = strokeColor.cgColor
            shapeLayer.fillColor = UIColor.clear.cgColor
            shapeLayer.lineWidth = lineWidth
            layer.addSublayer(shapeLayer)
        }
    }

    override public func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first as UITouch? {
            let touchPoint = touch.location(in: self)
            path.addLine(to: touchPoint)
            path.close()
            shapeLayer.path = path.cgPath
            shapeLayer.strokeColor = UIColor.clear.cgColor
            shapeLayer.fillColor = strokeColor.cgColor
            shapeLayer.lineWidth = lineWidth
            layer.addSublayer(shapeLayer)
        }
    }

所以我在更改区域时遇到问题。如何更改填充颜色的区域？或者如何修改没有点的路径with/or？

需要的步骤： - select 带手势的框架； - 填色; - 更新框架使其 bigger/smaller 带有手势（触摸 began/moved/ended）

类似于这个库https://github.com/TinyCrayon/TinyCrayon-iOS-SDK

Answer 1

您不能更改 CAShapeLayer。

但是我分两步就达到了这个效果

首先-select一个有bezierPath的区域，保存路径。

其次 - 创建 CGContext，使用 bezierPath 填充颜色在我们的图像上添加图像，然后使用我们的路径添加遮罩并添加功能 erase/unerase 图像。

如何更改 CAShapeLayer 内的区域？

How to change area inside CAShapeLayer?

core-graphics

cashapelayer

uibezierpath

swift