public void ExportDataSetToExcel(DataTable dt)
{
    HttpResponse response = HttpContext.Current.Response;        
    response.Clear();
    response.Charset = "utf-8";
    response.ContentEncoding = Encoding.GetEncoding("utf-8"); 
    response.ContentType = "application/vnd.ms-excel";
    Random Rand = new Random(); int iNum = Rand.Next(10000, 99999);
    string extension = ".xls";
    string filenamepath = AppDomain.CurrentDomain.BaseDirectory + "graphs\\" + iNum + ".xls";        
    string file_path = "graphs/" + iNum + extension;

    response.AddHeader("Content-Disposition", "attachment;filename=\"" + iNum + "\"");
    string query = "insert into graphtable(graphtitle,graphpath,creategraph,year) VALUES('" + iNum.ToString() + "','" + file_path + "','" + true + "','" + DateTime.Now.Year.ToString() + "')";
    try
    {
        int n = connect.UpdateDb(query);
        if (n > 0)
        {
            resultLabel.Text = "Merge Successfull";
        }
        else
        {
            resultLabel.Text = " Merge Failed";
        }
        resultLabel.Visible = true;
    }
    catch { }    
    using (StringWriter sw = new StringWriter())
    {
        using (HtmlTextWriter htw = new HtmlTextWriter(sw))
        {
            // instantiate a datagrid
            DataGrid dg = new DataGrid();
            dg.DataSource = dt; //ds.Tables[0];
            dg.DataBind();                
            dg.RenderControl(htw);
            File.WriteAllText(filenamepath, sw.ToString());    // File.WriteAllText(filenamepath, sw.ToString(), Encoding.UTF8);
            response.Write(sw.ToString());
            response.End();
        }
    }
}

Hi all,

I have created an excel sheet from datatable using above function. I want to read the excel sheet programatically using the below connectionstring. This string works fine for all other excel sheets but not for the one i created using the above function. I guess it is because of excel version problem.

   OleDbConnection conn= new OleDbConnection("Data Source='" + path +"';provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=Excel 8.0;";);  

Can anyone suggest a way by which i can create an excel sheet such that it is readable again using above query. I cannot use Microsoft InterOp library as it is not supported by my host.