asp.net GDI+ 绘制椭圆 ，弧线，扇形

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 using System.Web.UI;
 using System.Web.UI.WebControls;
 using System.Drawing;
 using System.Drawing.Drawing2D;

 public partial class _Default : System.Web.UI.Page
 {
     protected void Page_Load(object sender, EventArgs e)
     {
         Bitmap bitmap = new Bitmap(, );
         Graphics g = Graphics.FromImage(bitmap);
         g.Clear(Color.White);
         Pen pen = new Pen(Color.Blue, );
         Rectangle[] rects = { new Rectangle(, , , ), new Rectangle(, , , ), new Rectangle(, , , ) };
         g.DrawEllipse(pen, rects[]);//绘制椭圆
         pen.Color = Color.Red;
         g.DrawArc(pen, rects[], -, );//绘制弧线
         pen.Color = Color.Turquoise;
         g.DrawPie(pen, rects[], , -);//绘制扇形
         System.IO.MemoryStream ms = new System.IO.MemoryStream();
         bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
         Response.ClearContent();
         Response.ContentType = "image/Jpeg";
         Response.BinaryWrite(ms.ToArray());
     }
 }