chart1.ChartAreas.Clear();
            chart1.Series.Clear();
            chart1.Annotations.Clear();
            chart1.Legends.Clear();
            chart1.Titles.Clear();
            Title t = new Title("委案情况分析");
            t.Alignment = ContentAlignment.MiddleLeft;
            t.TextOrientation = TextOrientation.Stacked;
            t.IsDockedInsideChartArea = false;
            t.Font = new System.Drawing.Font("黑体", 20, FontStyle.Bold);
            chart1.Titles.Add(t);
            ChartArea c1 = new ChartArea("C1");
            c1.AxisX.IntervalType = DateTimeIntervalType.Days;//X轴以天数为间隔
            c1.AxisX.Interval = 1; //X轴刻度的间隔为1
            c1.AxisX.IntervalAutoMode = IntervalAutoMode.VariableCount; 
            c1.AxisX.MajorGrid.Enabled = false; //不显示网格线
            c1.AxisY.MajorGrid.Enabled = false; 
            chart1.ChartAreas.Add(c1);
            Series s1 = new Series("S1");
            s1.ChartType = SeriesChartType.Spline; //画表类型
            Random rnd = new Random();
            for (int i = 0; i < 10; i++)
            {
                DateTime date = DateTime.Now.AddDays(i);
                DataPoint d = new DataPoint(); //要显示的数据
                d.XValue =     date.ToOADate(); //X轴的值，DataPoint只接收double类型
                d.YValues[0] = rnd.NextDouble(); //Y轴的值
                s1.Points.Add(d);
            }
            chart1.Series.Add(s1);

------解决方案--------------------
office 有个一个空间 OWC11或者OWC10

Chart来操作，非常的方便，数据抓出来就可以直接显示

------解决方案--------------------

using System;  
using System.Collections;  
using System.Configuration;  
using System.Data;  
using System.Web;  
using System.Web.Security;  
using System.Web.UI;  
using System.Web.UI.HtmlControls;  
using System.Web.UI.WebControls;  
using System.Web.UI.WebControls.WebParts;  
//添加画图类  
using System.Drawing.Drawing2D;  
using System.Drawing.Imaging;  
using System.Drawing;  
using System.IO;  
using System.Data.SqlClient;  
public partial class Curve_Default : System.Web.UI.Page  
{  
protected void Page_Load(object sender, EventArgs e)  
{  
if (!IsPostBack)  
{  
Get_CurveData();  
}  
}  
//获取数据  
public void Get_CurveData()  
{  
SqlConnection conn = null;  
try  
{  
conn = CommonFunction.CreateDBTest();  
conn.Open();  
SqlCommand cmd = conn.CreateCommand();  
string sqlStr = "SELECT * FROM CURVE ORDER BY TESTDATE";  
DataTable dt = CommonFunction.ExecuteDatable(conn, cmd, CommandType.Text, sqlStr, null);  
draw(dt);  
}  
catch (Exception exp)  
{  
Response.Write(exp.Message);  
}  
finally  
{  
if (conn != null)  
conn.Close();  
}  
}  
public void draw(DataTable dt)  
{  
//取得记录数量  
int count = dt.Rows.Count;  
//记算图表宽度  
int wd = 80 + 20 * (count - 1);  
//设置最小宽度为800  
if (wd < 600) wd = 600;  
//生成Bitmap对像  
Bitmap img = new Bitmap(wd, 400);  
//生成绘图对像  
Graphics g = Graphics.FromImage(img);  
//定义黑色画笔  
Pen Bp = new Pen(Color.Black);  
//定义红色画笔  
Pen Rp = new Pen(Color.Red);  
//定义银灰色画笔  
Pen Sp = new Pen(Color.Silver)