/// <summary>

     /// 获取数据

     /// strChartName：图名称；

     /// yName：纵坐标名称；

     /// xName：横坐标名称；

     /// iyMaxValue:纵坐标最大值；

     /// dyAveValue:纵坐标单位值=（纵坐标最大值/标量30）

     /// ----100   30    :3

     /// ----200   30    :1.5；

     /// xdbColumnName:横坐标绑定显示数据表值的列名；

     /// ydbColumnName:纵坐标绑定显示数据表值得列名；

     /// </summary>

     public void Get_CurveData(string strSql,string strChartName,string yName,string xName,int iyMaxValue, double dyAveValue,string xdbColumnName,string ydbColumnName)

     {

         try

         {

             DataSet ds = sqlAccess.ReadFromDB(strSql);

             draw(ds.Tables[], strChartName, yName, xName, iyMaxValue, dyAveValue, xdbColumnName, ydbColumnName);

         }

         catch (Exception exp)

         {

             Response.Write(sqlAccess.ExceptionMessage);

         }

     }

     public void draw(DataTable dt, string strChartName, string yName, string xName, int iyMaxValue, double dyAveValue, string xdbColumnName, string ydbColumnName)

     {

         //取得记录数量

         int count = dt.Rows.Count;

         //记算图表宽度

         int wd =  +  * (count - );

         //设置最小宽度为800

         if (wd < ) wd = ;

         //生成Bitmap对像

         Bitmap img = new Bitmap(wd, );

         //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);

         //定义蓝色画笔

         Pen Blp = new Pen(Color.Blue);

         //定义大标题字体

         Font Bfont = new Font("Arial", , FontStyle.Bold);

         //定义一般字体

         Font font = new Font("Arial", );

         //定义大点的字体

         Font Tfont = new Font("Arial", );

         //定义横坐标间隔，(最佳值是总宽度-留空宽度[左右侧都需要])/(记录数量-1)

         int xSpace = (wd - ) / (count - );

         //定义纵坐标间隔,不能随便修改，跟高度和横坐标线的条数有关，最佳值=(绘图的高度-上面留空-下面留空)

         int ySpace = ;

         //纵坐标最大值和间隔值

         int yMaxValue = iyMaxValue;

         //绘制底色

         g.DrawRectangle(new Pen(Color.White, ), , , img.Width, img.Height);

         //定义黑色过渡型笔刷

         LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(, , img.Width, img.Height), Color.Black, Color.Black, 1.2F, true);

         //定义蓝色过渡型笔刷

         LinearGradientBrush Bluebrush = new LinearGradientBrush(new Rectangle(, , img.Width, img.Height), Color.Blue, Color.Blue, 1.2F, true);

         //绘制大标题

         g.DrawString(strChartName, Bfont, brush, , );

         //绘制信息简报

         //string info = " 曲线图生成时间：" + DateTime.Now.ToString();

         //g.DrawString(info, Tfont, Bluebrush, 40, 25);

         //绘制图片边框

         g.DrawRectangle(Bp, , , img.Width - , img.Height - );

         //绘制竖坐标轴

         g.DrawLine(Bp, , , , );

         //绘制横坐标轴 x2的60是右侧空出部分

         g.DrawLine(Bp, , ,  + xSpace * (count - ), );

         //绘制竖坐标标题

         g.DrawString(yName, Tfont, brush, , );

         //绘制横坐标标题

         g.DrawString(xName, Tfont, brush, , );

         //绘制竖坐标线

         for (int i = ; i < count; i++)

         {

             g.DrawLine(Sp,  + xSpace * i, ,  + xSpace * i, );

         }

         //绘制时间轴坐标标签

         for (int i = ; i < count; i++)

         {

             //string st = Convert.ToDateTime(dt.Rows[i]["testdate"]).ToString("MM:dd");

             //string st = "第" + dt.Rows[i]["testdate"].ToString() + "周";

             string st = dt.Rows[i][xdbColumnName].ToString();

             g.DrawString(st, font, brush,  + xSpace * i, );

         }

         //绘制横坐标线

         for (int i = ; i < ; i++)

         {

             g.DrawLine(Sp, ,  + ySpace * i,  + xSpace * (count - ),  + ySpace * i);

             //横坐标轴的值间隔是最大值除以间隔数

             int s = yMaxValue - i * (yMaxValue / );

             //绘制发送量轴坐标标签

             g.DrawString(s.ToString(), font, brush, ,  + ySpace * i);

         }

         //处理39.6%形式的数据

         string[] strArr = new string[dt.Rows.Count];

         for (int i = ; i < count; i++)

         {

             string strValue = dt.Rows[i][ydbColumnName].ToString();

             if (strValue.Contains("%"))

             {

                 strArr[i] = strValue.Split('%')[];

             }

             else

             {

                 strArr[i] = strValue;

             }

         }

         //200/30

         //定义纵坐标单位数值=纵坐标最大值/标量最大值

         double yAveValue = dyAveValue;

         //定义曲线转折点

         Point[] p = new Point[count];

         for (int i = ; i < count; i++)

         {

             p[i].X =  + xSpace * i;

             p[i].Y =  - Convert.ToInt32(Convert.ToDouble(strArr[i]) * yAveValue);

         }

         //绘制折线图

         //g.DrawLines(Rp, p);

         //绘制曲线图

         //g.DrawCurve(Rp, p);

         //绘制自定义张力的曲线图（0.5F是张力值，默认就是这个值）

         g.DrawCurve(Rp, p, 0.5F);

         //g.DrawLines(Rp, p);

         //当需要在一个图里绘制多条曲线的时候，就多定义个point数组，然后画出来就可以了。

         for (int i = ; i < count; i++)

         {

             //绘制发送记录点的发送量

             g.DrawString(strArr[i], font, Bluebrush, p[i].X, p[i].Y - );

             //绘制发送记录点

             g.DrawRectangle(Rp, p[i].X - , p[i].Y - , , );

         }

         ///*******************画中值线///

         //for (int i = 0; i < count; i++)

         //{

         //    p[i].X = 40 + xSpace * i;

         //    p[i].Y = 360 - Convert.ToInt32("50") * yAveValue;

         //}

         //for (int i = 0; i < count; i++)

         //{

         //    //绘制发送记录点的发送量

         //    g.DrawString("", font, Bluebrush, p[i].X, p[i].Y - 10);

         //    //绘制发送记录点

         //    g.DrawRectangle(Rp, p[i].X - 1, p[i].Y - 1, 2, 2);

         //}

         //g.DrawLine(Blp, 40, 360 - Convert.ToInt32("50") * yAveValue, 60 + xSpace * (count - 1), 360 - Convert.ToInt32("50") * yAveValue);

         ///**************************///

         //保存绘制的图片

         MemoryStream stream = new MemoryStream();

         img.Save(stream, ImageFormat.Jpeg);

         //图片输出

         Response.Clear();

         Response.ContentType = "image/jpeg";

         Response.BinaryWrite(stream.ToArray());

     }

 }