DiagonalLine.swift

class DrawView: UIView {
    override init(frame: CGRect) {
        super.init(frame: frame)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func draw( _ rect: CGRect) {
        drawLine(x: Int(bounds.origin.x), y: Int(bounds.origin.y), width: Int(bounds.width), height: Int(bounds.height))
    }
    
    func drawLine(x:Int, y:Int, width:Int, height:Int) {
        let path = UIBezierPath()
        path.move(to: CGPoint(x: x, y: y))
        path.addLine(to: CGPoint(x: x + width, y: y + height))
        path.close()
        UIColor.red.set()
        path.stroke()
        path.fill()
    }
}