绘制到CGContext时如何设置UIBezierPath的线宽？

Question

我正在尝试使用提供的UIBezierPath创建UIImage。不幸的是，无论我将setLineWidth设置为什么，结果总是笔划为1点：

extension UIBezierPath {
    func image(fillColor: UIColor, strokeColor: UIColor) -> UIImage? {
        UIGraphicsBeginImageContextWithOptions(bounds.size, false, 1.0)
        guard let context = UIGraphicsGetCurrentContext() else {
            return nil
        }

        context.setLineWidth(10)
        context.setFillColor(fillColor.cgColor)
        context.setStrokeColor(strokeColor.cgColor)

        self.fill()
        self.stroke()

        let image = UIGraphicsGetImageFromCurrentImageContext()

        UIGraphicsEndImageContext()

        return image
    }
}

在带有圆圈的测试项目中进行尝试，例如：

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()

        let imageView = UIImageView()
        imageView.frame = CGRect(x: 100, y: 100, width: 100, height: 100)
        view.addSubview(imageView)

        let bezierPath = UIBezierPath(ovalIn: CGRect(x: 0, y: 0, width: 100, height: 100))

        let image = bezierPath.image(fillColor: UIColor.blue, strokeColor: UIColor.red)

        imageView.image = image
    }
}

无论我将setLineWidth设置为什么，它总是看起来是1点。

Answer 1

您正在stroke上调用UIBezierPath，因此您需要使用lineWidth来设置self.lineWidth = 10的属性。

extension UIBezierPath {
    func image(fillColor: UIColor, strokeColor: UIColor) -> UIImage? {
        UIGraphicsBeginImageContextWithOptions(bounds.size, false, 1.0)
        guard let context = UIGraphicsGetCurrentContext() else {
            return nil
        }

        context.setFillColor(fillColor.cgColor)
        self.lineWidth = 10
        context.setStrokeColor(strokeColor.cgColor)

        self.fill()
        self.stroke()

        let image = UIGraphicsGetImageFromCurrentImageContext()

        UIGraphicsEndImageContext()

        return image
    }
}