using System;
using System.Collections.Generic;
using System.Text;
//
//using System.Data;
//using System.Web.UI.WebControls;
//
using System.Drawing;
using System.Drawing.Imaging;
 
namespace Tools
{
    public static class OWCImageHelp
    {
        /// <summary>
        /// 动态的生成柱状图和饼状图
        /// </summary>
        /// <param name="arrValueNames">行坐标要显示的字段</param>
        /// <param name="arrValues">纵坐标要显示的数字</param>
        /// <param name="title">标题</param>
        public static void GetZBImage(string[] arrValueNames, int[] arrValues, string title)
        {
            Bitmap objBitMap = new Bitmap(650, 300);
            Graphics objGraphics;
            objGraphics = Graphics.FromImage(objBitMap);
            objGraphics.Clear(Color.White);
            //int[] arrValues = { 40000, 32000, 24000, 30000, 36000, 28000 };
            //string[] arrValueNames = new string[] { "第一次", "第二次", "第三次", "第四次", "第五次", "第六次" };
            objGraphics.DrawString(title, new System.Drawing.Font("宋体", 16), Brushes.Blue, new PointF(5, 5));
            PointF symbolLeg = new PointF(335, 20);
            PointF descLeg = new PointF(360, 16);
            //画出说明部分的图形
            for (int i = 0; i < arrValueNames.Length; i++)
            {
                objGraphics.FillRectangle(new SolidBrush(GetColor(i)), symbolLeg.X, symbolLeg.Y, 20, 10);
                objGraphics.DrawRectangle(Pens.Black, symbolLeg.X, symbolLeg.Y, 20, 10);
                objGraphics.DrawString(arrValueNames[i].ToString(), new System.Drawing.Font("宋体", 10), Brushes.Black, descLeg);
                symbolLeg.Y += 15;
                descLeg.Y += 15;
            }
            float TotalValues = 0;
            for (int i = 0; i <= arrValues.Length - 1; i++)
            {
                TotalValues += arrValues[i];
            }
            //绘出矩形图。
            float Rectangleheight = 0;
            PointF recLeg = new PointF(12, 200 - arrValues[0] / TotalValues * 300);
            for (int i = 0; i < arrValues.Length; i++)
            {
                Rectangleheight = arrValues[i] / TotalValues * 300;
                objGraphics.FillRectangle(new SolidBrush(GetColor(i)), (i * 35) + 15, 200 - Rectangleheight, 20, Rectangleheight + 50);
                objGraphics.DrawRectangle(Pens.Black, (i * 35) + 15, 200 - Rectangleheight, 20, Rectangleheight + 50);
                recLeg.Y = 200 - Rectangleheight - 14;
                objGraphics.DrawString(arrValues[i].ToString(), new System.Drawing.Font("宋体", 10), Brushes.Blue, recLeg);
                recLeg.X += 35;
            }
            //绘出圆形图。
            float sglCurrentAngle = 0;
            float sglTotalAngle = 0;
            for (int i = 0; i < arrValues.Length; i++)
            {
                sglCurrentAngle = arrValues[i] / TotalValues * 360;
                objGraphics.FillPie(new SolidBrush(GetColor(i)), 220, 95, 100, 100, sglTotalAngle, sglCurrentAngle);
                objGraphics.DrawPie(Pens.Black, 220, 95, 100, 100, sglTotalAngle, sglCurrentAngle);
                sglTotalAngle += sglCurrentAngle;
            }
            objBitMap.Save(System.Web.HttpContext.Current.Response.OutputStream, ImageFormat.Gif);
        }
        //定义颜色。
        private static Color GetColor(int itemIndex)
        {
            Color objColor;
            if (itemIndex == 0)
            {
                objColor = Color.Maroon;
            }
            else if (itemIndex == 1)
            {
                objColor = Color.Red;
            }
            else if (itemIndex == 2)
            {
                objColor = Color.Gray;
            }
            else if (itemIndex == 3)
            {
                objColor = Color.Blue;
            }
            else if (itemIndex == 4)
            {
                objColor = Color.Orange;
            }
            else if (itemIndex == 5)
            {
                objColor = Color.Cyan;
            }
            else if (itemIndex == 6)
            {
                objColor = Color.Bisque;
            }
            else if (itemIndex == 7)
            {
                objColor = Color.Maroon;
            }
            else if (itemIndex == 8)
            {
                objColor = Color.Maroon;
            }
            else
            {
                objColor = Color.Blue;
            }
            return objColor;
        }
    }
}

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using BLL;
using Models;
public partial class GridViewDemo_BZImage : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        GetBZIamge();
    }
    /// <summary>
    /// 生成饼状柱状图
    /// </summary>
    public void GetBZIamge()
    {
        DataTable dt = BLL.StudentBLL.SelAllStudent();
        string[] rows = new string[dt.Rows.Count];
        int[] columns = new int[dt.Rows.Count];
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            rows[i] = dt.Rows[i]["学生姓名"].ToString();
            columns[i] = Convert.ToInt32(dt.Rows[i]["薪金"].ToString());
        }
        Tools.OWCImageHelp.GetZBImage(rows, columns, "学生薪水查询");
    }
}

<table style="width: 600px" onMouseOver="over()" onMouseOut="out()">
            <tr>
             <td style="height: 21px; width: 35px;" align="center">
                    <img id="BZImage" src="BZImage.aspx" alt=""/>
                </td>
            </tr>
</table>