Export Data to Excel

First get the data in a DataTable and call the below function.

  if (dtGetData.Rows.Count > 0)
         {
         string filename = "ExcelName.xls";
         System.IO.StringWriter tw = new System.IO.StringWriter();
        System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter(tw);
         DataGrid dgGrid = new DataGrid();
         dgGrid.DataSource = dtGetData;
         dgGrid.DataBind();        
         dgGrid.RenderControl(hw);           
         Response.ContentType = "application/vnd.ms-excel";
         Response.AppendHeader("Content-Disposition", "attachment; filename=" + filename + "");
         this.EnableViewState = false;
         Response.Write(tw.ToString());
         Response.End();
         }