以下代码可以在屏幕上画出一个自定义的坐标系，该坐标系以屏幕左上角为原点：Graphics g = e.Graphics; Pen pen = new Pen(Color.Black, 1); float x0 = ClientRectangle.Width / 2.0F;float y0 = ClientRectangle.Height / 2.0F; g.TranslateTransform(x0, y0);g.ScaleTransform(1, -1);g.DrawLine(pen, -x0, 0, x0, 0);g.DrawLine(pen, x0 - 5F, 5F, x0, 0);g.DrawLine(pen, x0 - 5F, -5F, x0, 0);g.DrawLine(pen, 0, -y0, 0, y0);g.DrawLine(pen, -5F, y0 - 5F, 0, y0);