使用CoreGraphics框架进行擦除或透明笔划问题

class CustomView: UIView {
    override func draw(_ rect: CGRect) {
        super.draw(rect)
        
        guard let context = UIGraphicsGetCurrentContext() else { return }
        
        context.setLineWidth(10)
        context.setStrokeColor(UIColor.black.cgColor)
        context.setBlendMode(.clear)
        
        context.move(to: CGPoint(x: 50, y: 50))
        context.addLine(to: CGPoint(x: 100, y: 100))
        context.strokePath()
        
        context.clear(CGRect(x: 50, y: 50, width: 50, height: 50))
    }
}