private void ExportGridView()
{
System.IO.StringWriter sw = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter htw = new System.Web.UI.HtmlTextWriter(sw);
gvFiles.FooterRow.Visible = false;
gvFiles.RenderControl(htw);
string renderedGridView = sw.ToString();
File.WriteAllText(@"D:\Suresh\ExportedFile.xls", renderedGridView);
gvFiles.FooterRow.Visible = true;
}