ASP.NET绘制折线图代码分享

/// <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[0], 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 = 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);
        //定义蓝色画笔
        Pen Blp = new Pen(Color.Blue);
        //定义大标题字体 
        Font Bfont = new Font("Arial", 12, FontStyle.Bold);
        //定义一般字体 
        Font font = new Font("Arial", 9);
        //定义大点的字体 
        Font Tfont = new Font("Arial", 9);
        //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 - 100) / (count - 1);
        //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 = 30;
        //纵坐标最大值和间隔值 
        int yMaxValue = iyMaxValue;
        //绘制底色 
        g.DrawRectangle(new Pen(Color.White, 400), 0, 0, img.Width, img.Height);
        //定义黑色过渡型笔刷 
        LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, 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(0, 0, img.Width, img.Height), Color.Blue, Color.Blue, 1.2F, true);
        //绘制大标题 
        g.DrawString(strChartName, Bfont, brush, 40, 5);
        //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, 0, 0, img.Width - 1, img.Height - 1);
        //绘制竖坐标轴 
        g.DrawLine(Bp, 40, 55, 40, 360);
        //绘制横坐标轴 x2的60是右侧空出部分 
        g.DrawLine(Bp, 40, 360, 60 + xSpace * (count - 1), 360);
        //绘制竖坐标标题 
        g.DrawString(yName, Tfont, brush, 5, 40);
        //绘制横坐标标题 
        g.DrawString(xName, Tfont, brush, 40, 385);
        //绘制竖坐标线 
        for (int i = 0; i < count; i++)
        {
            g.DrawLine(Sp, 40 + xSpace * i, 60, 40 + xSpace * i, 360);
        }
        //绘制时间轴坐标标签 
        for (int i = 0; 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, 30 + xSpace * i, 370);
        }
        //绘制横坐标线 
        for (int i = 0; i < 10; i++)
        {
            g.DrawLine(Sp, 40, 60 + ySpace * i, 40 + xSpace * (count - 1), 60 + ySpace * i);
            //横坐标轴的值间隔是最大值除以间隔数 
            int s = yMaxValue - i * (yMaxValue / 10);
            //绘制发送量轴坐标标签 
            g.DrawString(s.ToString(), font, brush, 10, 60 + ySpace * i);
        }

        //处理39.6%形式的数据
        string[] strArr = new string[dt.Rows.Count];
        for (int i = 0; i < count; i++)
        {
            string strValue = dt.Rows[i][ydbColumnName].ToString();
            if (strValue.Contains("%"))
            {
                strArr[i] = strValue.Split('%')[0];
            }
            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 = 0; i < count; i++)
        {
            p[i].X = 40 + xSpace * i;
            p[i].Y = 360 - 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 = 0; 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 - 10);
            //绘制发送记录点 
            g.DrawRectangle(Rp, p[i].X - 1, p[i].Y - 1, 2, 2);
        }

        ///*******************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());
    } 
}