using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Collections;


public class LineChart
{
    public Bitmap Bitmapb;
    public string strTitle = "Default Title";
    public ArrayList ArrayListchartValues = new ArrayList();
    public float ftXorigin = 0, ftYorigin = 0;
    public float ftScaleX, ftScaleY;
    public float ftXdivs = 2, ftYdivs = 2;
    private int intWidth, intHeight;
    private Graphics Graphicsg;
    private Page Pagep;

    struct datapoint
    {
        public float ftx;
        public float fty;
        public bool bolvalid;
    }
    //initialize

    public LineChart(int intmyWidth, int intmyHeight, Page myPage)
    {
        intWidth = intmyWidth; intHeight = intmyHeight;
        ftScaleX = intmyWidth; ftScaleY = intmyHeight;
        Bitmapb = new Bitmap(intmyWidth, intmyHeight);
        Graphicsg = Graphics.FromImage(Bitmapb);
        Pagep = myPage;
    }
    public void AddValue(int intx, int inty)
    {
        datapoint myPoint;
        myPoint.ftx = intx;
        myPoint.fty = inty;
        myPoint.bolvalid = true;
        ArrayListchartValues.Add(myPoint);

    }
    public void Draw()

    {

        int inti;
        float ftx, fty, ftx0, fty0;
        string strmyLabel;
        Pen penblackPen = new Pen(Color.Black,1);
        Brush BrushblackBrush = new SolidBrush(Color.Black);
        Font FontaxesFont = new Font("arial",10);

        //first establish working area

        Pagep.Response.ContentType="image/jpeg";
        Graphicsg.FillRectangle(new
        SolidBrush(Color.LightYellow),0,0,intWidth,intHeight);
        int intChartInset = 50;
        int intChartWidth = intWidth-(2*intChartInset);
        int intChartHeight = intHeight-(2*intChartInset);
        Graphicsg.DrawRectangle(new Pen(Color.Black,1),intChartInset,intChartInset,intChartWidth,intChartHeight);
        //must draw all text items before doing the rotate below
        Graphicsg.DrawString(strTitle, new Font("arial",14), BrushblackBrush, intWidth/3, 10);
        //draw X axis labels
        for(inti=0; inti<=ftXdivs; inti++)

        {

            ftx=intChartInset+(inti*intChartWidth)/ftXdivs;
            fty=intChartHeight+intChartInset;
            strmyLabel = (ftXorigin + (ftScaleX*inti/ftXdivs)).ToString();
            Graphicsg.DrawString(strmyLabel, FontaxesFont, BrushblackBrush, ftx-4, fty+10);
            Graphicsg.DrawLine(penblackPen, ftx, fty+2, ftx, fty-2);
        }

        //draw Y axis labels
        for(inti=0; inti<=ftYdivs; inti++)

        {

            ftx=intChartInset;
            fty=intChartHeight+intChartInset-(inti*intChartHeight/ftYdivs);
            strmyLabel = (ftYorigin + (ftScaleY*inti/ftYdivs)).ToString();
            Graphicsg.DrawString(strmyLabel, FontaxesFont, BrushblackBrush, 5, fty-6);
            Graphicsg.DrawLine(penblackPen, ftx+2, fty, ftx-2, fty);

        }

 

        //transform drawing coords to lower-left (0,0)

        Graphicsg.RotateTransform(180);
        Graphicsg.TranslateTransform(0,-intHeight);
        Graphicsg.TranslateTransform(-intChartInset,intChartInset);
        Graphicsg.ScaleTransform(-1, 1);

 

        //draw chart data

        datapoint datapointprevPoint = new datapoint();
        datapointprevPoint.bolvalid=false;

        foreach(datapoint myPoint in ArrayListchartValues)
            
        {

            if(datapointprevPoint.bolvalid==true)

            {

                ftx0=intChartWidth*(datapointprevPoint.ftx-ftXorigin)/ftScaleX;
                fty0=intChartHeight*(datapointprevPoint.fty-ftYorigin)/ftScaleY;
                ftx=intChartWidth*(myPoint.ftx-ftXorigin)/ftScaleX;
                fty=intChartHeight*(myPoint.fty-ftYorigin)/ftScaleY;
                Graphicsg.DrawLine(penblackPen,ftx0,fty0,ftx,fty);
                Graphicsg.FillEllipse(BrushblackBrush,ftx0-2,fty0-2,4,4);
                Graphicsg.FillEllipse(BrushblackBrush,ftx-2,fty-2,4,4);

            }

            datapointprevPoint = myPoint;

        }

        //finally send graphics to browser
        Bitmapb.Save(Pagep.Response.OutputStream, ImageFormat.Jpeg);

    }
    LineChart()

    {

        Graphicsg.Dispose();

        Bitmapb.Dispose();

    }

}

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add a default.aspx and add the following code in page load


default.aspx.cs
-----------------
 protected void Page_Load(object sender, EventArgs e)
    {
        LineChart c = new LineChart(640, 480, Page);
        c.strTitle = "My Line Chart";
        c.ftXorigin = 0;
        c.ftScaleX = 500; 
        c.ftXdivs = 5;
        c.ftYorigin = 0;
        c.ftScaleY = 1000;
        c.ftYdivs = 5;
        c.AddValue(50, 50);
        c.AddValue(100, 100);
        c.AddValue(200, 150);
        c.AddValue(450, 450);
        c.Draw();


    }