如何利用.net　绘制一个饼图？
我根据这个例子：
http://www.opent.cn/a/101/2367.shtml
绘制了柱形图，
请问如何绘制饼图？

------解决方案--------------------
<%@ Page Language="C#" ContentType="text/html" ResponseEncoding="utf-8" Debug="true" %>
<!-- for .Net Framework 2.0 -->
<%@ Import Namespace="System.Drawing" %>
<script runat="server" language="c#">
void Page_Load(object sender, EventArgs e){
Bitmap image = new Bitmap(440,300);
Graphics g = Graphics.FromImage(image);
  
g.Clear(Color.White);
  
Rectangle outline = new Rectangle(10, 10, 420, 240);
  
g.DrawEllipse(new Pen(Color.Black, 4f), outline);

//create data 
int[] b = new int[]{1565, 486, 5896, 1449};

float count = b[0] + b[1] + b[2] + b[3];
float[] c = new float[]{(b[0]/count), (b[1]/count), (b[2]/count), (b[3]/count)};
float[] a = new float[]{(360 * c[0]), (360 * c[1]), (360 * c[2]), (360 * c[3])};
  
//make area pie
g.FillPie(new SolidBrush(Color.Red), outline, 0f, a[0]);
g.FillPie(new SolidBrush(Color.Yellow), outline, a[0], a[1]);
g.FillPie(new SolidBrush(Color.Blue), outline, (a[0] + a[1]), a[2]);
g.FillPie(new SolidBrush(Color.Green), outline, (a[0] + a[1] + a[2]), a[3]);
  
//make color note start---
g.DrawRectangle(new Pen(Color.Black, 1f), new Rectangle(10, 260, 10, 10));
g.FillRectangle(new SolidBrush(Color.Red), 10, 260, 10, 10);
g.DrawString("1item:" + b[0].ToString(), new Font("Black", 10), new SolidBrush(Color.Black), 25, 260);
  
g.DrawRectangle(new Pen(Color.Black, 1f), new Rectangle(110, 260, 10, 10));
g.FillRectangle(new SolidBrush(Color.Yellow), 110, 260, 10, 10);
g.DrawString("2item:" + b[1].ToString(), new Font("Black", 10), new SolidBrush(Color.Black), 125, 260);
  
g.DrawRectangle(new Pen(Color.Black, 1f), new Rectangle(210, 260, 10, 10));
g.FillRectangle(new SolidBrush(Color.Blue), 210, 260, 10, 10);
g.DrawString("3item:" + b[2].ToString(), new Font("Black", 10), new SolidBrush(Color.Black), 225, 260);
  
g.DrawRectangle(new Pen(Color.Black, 1f), new Rectangle(310, 260, 10, 10));
g.FillRectangle(new SolidBrush(Color.Green), 310, 260, 10, 10);
g.DrawString("4item:s" + b[3].ToString(), new Font("Black", 10), new SolidBrush(Color.Black), 325, 260);
//make color note end---
  
//mark string
g.DrawString(".Net Drawing", new Font("Arial Black", 20), new SolidBrush(Color.White), 100, 80);
  
image.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Gif);
//Response.Write(a[0]+"/"+a[1]+"/"+a[2]+"/"+a[3]);
//Response.Write((b[0]/(float)count*100));
Response.ContentType="Image/Gif";
}
</script>
------解决方案--------------------
zedgraph,ms chart,OWC都可
柱状图, 折线图, 扇形图
------解决方案--------------------
我用的是webchart.dll控件，根据从数据库中读出的数据，可以生成饼图或其它的图形。