Use the following code.its working for me..
Response.Clear();
Response.AddHeader("content-disposition", "attachment;filename=REPORTNAME.xls");
Response.Charset = "iso-8859-2";
Response.ContentType = "application/ms-excel";
using (StringWriter StringWriter = new System.IO.StringWriter())
{
using (HtmlTextWriter HtmlTextWriter = new HtmlTextWriter(StringWriter))
{
GridViewName.AllowPaging = false;
GridViewName.Attributes.AddAttributes(HtmlTextWriter);
GetUserTaskDetails();
GridViewName.RenderControl(HtmlTextWriter);
}
Response.Write(str);
Response.Write(StringWriter.ToString());
}
Response.End();
GridViewName.AllowPaging = true;
Happy coding :-)JMD