在ASP.NET页面中实现数据棒图（转载）

首先看一下效果图（具体内容就看源码吧：）

源码：

using System;
using System.Data;
using System.Configuration;
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;
//下面程序中使用的ImageFormat类所在的命名空间
using System.Drawing.Imaging;
//下面程序中使用到关于数据库方面的类所在的命名空间
using System.Data.OleDb;
using System.Drawing;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        // 在此处放置用户代码以初始化页面
        string sRouter = "d:\\WebSite\\Bar\\App_Data\\db1.mdb";
        //获得当前Access数据库在服务器端的绝对路径
        string strCon = " Provider = Microsoft.Jet.OLEDB.4.0; Data Source = " + sRouter;
        //创建一个数据库连接
        OleDbConnection myConn = new OleDbConnection(strCon);
        string strCom = " SELECT YF ,SL FROM Table01 ORDER BY YF";
        myConn.Open();
        OleDbCommand myCommand = new OleDbCommand(strCom, myConn);
        OleDbDataReader myOleDbDataReader = myCommand.ExecuteReader();
        //创建OleDbDataReader实例，并以此实例来获取数据库中各条记录数据
        int[] iXiaoSH = new int[12];
        //定义一个数组，用以存放从数据库中读取的销售数据
        string[] sMoth = new string[12];
        //定义一个数组，用以存放从数据库中读取的销售月份
        int iIndex = 0;
        while (myOleDbDataReader.Read())
        {
            iXiaoSH[iIndex] = myOleDbDataReader.GetInt32(1);
            sMoth[iIndex] = myOleDbDataReader.GetInt32(0).ToString() + "月";
            iIndex++;
        }
        //读取Table01数据表中的各条数据，并存放在先前定义的二个数组中
        myConn.Close();
        myOleDbDataReader.Close();
        //关闭各种资源
        Bitmap bm = new Bitmap(600, 250);
        //创建一个长度为600，宽带为250的Bitmap实例
        Graphics g;
        g = Graphics.FromImage(bm);
        //由此Bitmap实例创建Graphic实例
        g.Clear(Color.Snow);
        //用Snow色彩为背景色填充此绘画图面
        g.DrawString(" ××公司××产品2004年度销售情况一览表", new Font("宋体", 16), Brushes.Black, new Point(5, 5));
        //在绘画图面的指定位置，以指定的字体、指定的颜色绘制指定的字符串。即为图表标题
        //以下代码是是实现图01中的右上部
        Point myRec = new Point(535, 30);
        Point myDec = new Point(560, 26);
        //以上是在图01中为下面绘制定位
        g.DrawString("单位：万件", new Font("宋体", 9), Brushes.Black, new Point(525, 12));
        for (int i = 0; i < sMoth.Length; i++)
        {
            g.DrawRectangle(Pens.Black, myRec.X, myRec.Y, 20, 10);
            //绘制小方块
            g.FillRectangle(new SolidBrush(GetColor(i)), myRec.X, myRec.Y, 20, 10);
            //填充小方块
            g.DrawString(sMoth[i].ToString(), new Font("宋体", 9), Brushes.Black, myDec);
            //绘制小方块右边的文字
            myRec.Y += 15;
            myDec.Y += 15;
        }
        //以下代码是绘制图01中的Bar图，及其销售数量
        int iBarWidth = 40;
        int scale = 10;
        for (int i = 0; i < iXiaoSH.Length; i++)
        {
            g.DrawRectangle(Pens.Black, (i * iBarWidth) + 15, 250 - (iXiaoSH[i] * scale), 20, (iXiaoSH[i] * scale) + 5);
            //绘制Bar图
            g.FillRectangle(new SolidBrush(GetColor(i)), (i * iBarWidth) + 15, 250 - (iXiaoSH[i] * scale), 20, (iXiaoSH[i] * scale) + 5);
            //以指定的色彩填充Bar图
            g.DrawString(iXiaoSH[i].ToString(), new Font("宋体", 9), Brushes.Black, (i * iBarWidth) + 20, 235 - (iXiaoSH[i] * scale));
            //显示Bar图代表的数据
        }
        //以下代码是绘制图01中的边框，并形成Jpeg文件，供浏览器显示出来
        Pen p = new Pen(Color.Black, 2);
        g.DrawRectangle(p, 1, 1, 598, 248);
        bm.Save(Response.OutputStream, ImageFormat.Jpeg);
    }
    private Color GetColor(int itemIndex)
    {
        Color MyColor;
        int i = itemIndex;
        switch (i)
        {
            case 0:
                MyColor = Color.Cornsilk;
                return MyColor;
            case 1:
                MyColor = Color.Red;
                return MyColor;
            case 2:
                MyColor = Color.Yellow;
                return MyColor;
            case 3:
                MyColor = Color.Peru;
                return MyColor;
            case 4:
                MyColor = Color.AliceBlue;
                return MyColor;
            case 5:
                MyColor = Color.Bisque;
                return MyColor;
            case 6:
                MyColor = Color.Gray;
                return MyColor;
            case 7:
                MyColor = Color.Maroon;
                return MyColor;
            case 8:
                MyColor = Color.Azure;
                return MyColor;
            case 9:
                MyColor = Color.Orange;
                return MyColor;
            case 10:
                MyColor = Color.Coral;
                return MyColor;
            case 11:
                MyColor = Color.BurlyWood;
                return MyColor;
            case 12:
                MyColor = Color.Chartreuse;
                return MyColor;
            default:
                MyColor = Color.Green;
                return MyColor;
        }
    }
}