how to Export Griedview data in Excel sheet ?

 

Response.Clear();
Response.Charset = "";
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.ContentType = "application/vnd.excel";
Response.AddHeader("content-disposition", "attachment;filename=" + filename + ".xls");
System.IO.StringWriter stringWrite = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter htmlWrite = new System.Web.UI.HtmlTextWriter(stringWrite);
GridView1.RenderControl(htmlWrite);
Response.Write(stringWrite.ToString());
Response.Flush();
Response.End();
stringWrite = null;
htmlWrite = null;