如何在windows应用程序中画线，请教一个完整的例子

Question

protected void Form1_Paint (object sender, System.WinForms.PaintEventArgs e)
{
Graphics g = e.Graphics;
Pen pen = new Pen(Color.Red, 9.0f); //使用不同的StartCap和EndCap绘制直线
pen.StartCap = LineCap.Flat;
pen.EndCap = LineCap.ArrowAnchor;
g.DrawLine(pen, new Point(10, 10), new Point(280, 10));
g.DrawString("LEFT: Flat, RIGHT: ArrowAnchor", this.Font,
new SolidBrush(Color.Black), 10, 15); pen.StartCap = LineCap.Triangle;
pen.EndCap = LineCap.DiamondAnchor;
g.DrawLine(pen, new Point(10, 35), new Point(280, 35));
g.DrawString("LEFT: Triangle, RIGHT: DiamondAnchor", this.Font,
new SolidBrush(Color.Black), 10, 40); pen.StartCap = LineCap.Square;
pen.EndCap = LineCap.SquareAnchor;
g.DrawLine(pen, new Point(10, 60), new Point(280, 60));
g.DrawString("LEFT: Square, RIGHT: SquareAnchor", this.Font,
new SolidBrush(Color.Black), 10, 65); pen.StartCap = LineCap.Round;
pen.EndCap = LineCap.RoundAnchor;
g.DrawLine(pen, new Point(10, 85), new Point(280, 85));
g.DrawString("LEFT: Round, RIGHT: RoundAnchor", this.Font,
new SolidBrush(Color.Black), 10, 90);
}