Generate Excel file on the fly without using Microsoft Excel and download it in a chunk-chunk way

Couple of days ago I was working with Excel file manipulation. The requirement was like that the file has to be created on the fly based on the data getting from database and then download it to the client PC. So what I did here is that, I have just created the excel file on the fly and send the data to the client in a chunk way. To do that, I wrote a handler which takes the key as the request, getting the data based on the key from the database, write the excel file and then download it to the chunk way. Fortunately, I have got an excellent article in code project which helped me for generating excel files without using Microsoft Excel.

The Handler class is given below,

public void ProcessRequest(HttpContext context)
{
    HttpRequest request = context.Request;   
    System.IO.MemoryStream currentStream = null;    
    byte[] buffer = new Byte[10000];   
    int length;  
    long dataToRead;    
    string fileName = request["FileName"];
    System.Collections.Generic.List<Test> lstTest = "Your List of Test Object";
    
    try
    {
        currentStream = new System.IO.MemoryStream();
        ExcelWriter writer = new ExcelWriter(currentStream);
        writer.BeginWrite();       
        writer.WriteCell(0, 0, "Title");
        writer.WriteCell(0, 1, "FirstName");
        writer.WriteCell(0, 2, "Surname");
        writer.WriteCell(0, 3, "Email");
        writer.WriteCell(0, 4, "TelePhoneNumber");
        writer.WriteCell(0, 5, "OrderNumber");
        writer.WriteCell(0, 6, "SubmissionDate");
        
        if (lstTest != null)
        {        
            for (int row = 0; row < lstTest.Count; row++)
            {
                writer.WriteCell(row + 1, 0, lstTest[row].Title);
                writer.WriteCell(row + 1, 1, lstTest[row].FirstName);
                writer.WriteCell(row + 1, 2, lstTest[row].SurName);
                writer.WriteCell(row + 1, 3, lstTest[row].Email);
                writer.WriteCell(row + 1, 4, lstTest[row].TelePhoneNumber);
                writer.WriteCell(row + 1, 5, lstTest[row].OrderNumber);
                writer.WriteCell(row + 1, 6, lstTest[row].SubmissionDate);
            }
        }
        writer.EndWrite();
        currentStream.Position = 0;
        context.Response.AddHeader("Content-Length", currentStream.Length.ToString());
        context.Response.AddHeader("Accept-Ranges", "bytes");
        context.Response.Buffer = false;
        context.Response.AddHeader("Connection", "Keep-Alive");
        context.Response.ContentType = "application/octet-stream";
        context.Response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
       
        dataToRead = currentStream.Length;
        context.Response.ContentType = "application/octet-stream";
       
        while (dataToRead > 0)
        {       
            if (context.Response.IsClientConnected)
            {            
                length = currentStream.Read(buffer, 0, 10000);            
                context.Response.OutputStream.Write(buffer, 0, length);            
                context.Response.Flush();
                buffer = new Byte[10000];
                dataToRead = dataToRead – length;
            }
            else
            {            
                dataToRead = -1;
            }
        }
    }
    catch (Exception ex)
    {
        context.Response.Write(ex);
    }
    finally
    {
        if (currentStream != null)
        {   
            currentStream.Close();
            currentStream.Dispose();
        }
    }
}

The Test Class is given below

public class Test
{    
    public Test()
    {
    }
    public string Title { get; set; }

    public string FirstName { get; set; }
    
    public string SurName { get; set; }
   
    public string Email { get; set; }
     
    public string TelePhoneNumber { get; set; }

    public string OrderNumber { get; set; }
   
    public string SubmissionDate { get; set; }  
}

public class ExcelWriter
{
    private Stream stream;
    private BinaryWriter writer;

    private ushort[] clBegin = { 0x0809, 8, 0, 0x10, 0, 0 };
    private ushort[] clEnd = { 0x0A, 00 };

    private void WriteUshortArray(ushort[] value)
    {
        for (int i = 0; i < value.Length; i++)
            writer.Write(value[i]);
    } 
    public ExcelWriter(Stream stream)
    {
        this.stream = stream;
        writer = new BinaryWriter(stream);
    }   
    public void WriteCell(int row, int col, string value)
    {
        ushort[] clData = { 0x0204, 0, 0, 0, 0, 0 };
        int iLen = value.Length;
        byte[] plainText = Encoding.ASCII.GetBytes(value);
        clData[1] = (ushort)(8 + iLen);
        clData[2] = (ushort)row;
        clData[3] = (ushort)col;
        clData[5] = (ushort)iLen;
        WriteUshortArray(clData);
        writer.Write(plainText);
    }   
    public void WriteCell(int row, int col, int value)
    {
        ushort[] clData = { 0x027E, 10, 0, 0, 0 };
        clData[2] = (ushort)row;
        clData[3] = (ushort)col;
        WriteUshortArray(clData);
        int iValue = (value << 2) | 2;
        writer.Write(iValue);
    }   
    public void WriteCell(int row, int col, double value)
    {
        ushort[] clData = { 0x0203, 14, 0, 0, 0 };
        clData[2] = (ushort)row;
        clData[3] = (ushort)col;
        WriteUshortArray(clData);
        writer.Write(value);
    }   
    public void WriteCell(int row, int col)
    {
        ushort[] clData = { 0x0201, 6, 0, 0, 0x17 };
        clData[2] = (ushort)row;
        clData[3] = (ushort)col;
        WriteUshortArray(clData);
    }  
    public void BeginWrite()
    {
        WriteUshortArray(clBegin);
    }   
    public void EndWrite()
    {
        WriteUshortArray(clEnd);
        writer.Flush();
    }
}