Draw line with oblique border

Question

How to draw line with oblique border like this:

I drew only a normal line:

CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, 30.f);
CGContextSetStrokeColorWithColor(context, [UIColor personalBlue].CGColor);
CGContextMoveToPoint(context, 0.f, 0.f);
CGContextAddLineToPoint(context,self.bounds.size.width, 0.f);
CGContextStrokePath(context);

Answer 1

I use CAShapeLayer:

class TriangleView: UIView {

    override func awakeFromNib() {
        super.awakeFromNib()
        self.contentMode = UIViewContentMode.redraw
    }

    override func draw(_ rect: CGRect) {
        let mask = CAShapeLayer()
        mask.frame = self.layer.bounds

        let width = self.layer.frame.size.width
        let height = self.layer.frame.size.height

        let path = CGMutablePath.init()

        path.move(to: CGPoint(x: width, y: 0))
        path.addLine(to: CGPoint(x: width, y: height))
        path.addLine(to: CGPoint(x: 0, y: height))
        path.addLine(to: CGPoint(x: 0, y: 0))
        path.addLine(to: CGPoint(x: 0, y: 50))

        mask.path = path

        self.layer.mask = mask

        let shape = CAShapeLayer()
        shape.frame = self.bounds
        shape.path = path
        shape.lineWidth = 3.0
        shape.strokeColor = UIColor.white.cgColor
        shape.fillColor = UIColor.white.cgColor

        self.layer.insertSublayer(shape, at: 0)
    }


}

The result is this: