public static void ToExcelOrWord(Control gvName,string contentType,string fileName)
{
   HttpContext.Current.Response.Clear();
   HttpContext.Current.Response.ClearContent();
   HttpContext.Current.Response.ClearHeaders();
   HttpContext.Current.Response.Charset="GB2312";
   HttpContext.Current.Response.Buffer=true;
   HttpContext.Current.Response.AppendHeader("Content-Disposition","attachment;filename="+HttpContext.Current.Server.UrlEncode(fileName));
   HttpContext.Current.Response.ContentEncoding=System.Text.Encoding.GetEncoding("GB2312");
   HttpContext.Current.Response.ContentType=contentType;
   gvName.Page.EnableViewState=false;
   System.Globalization.CultureInfo myCItrad=new System.Globalization.CultureInfo("ZH-CN",true);
   StringWriter stringWriter=new StringWriter(myCItrad);
   HtmlTextWriter htmlWriter=new HtmlTextWriter(stringWriter);
   gvName.RenderControl(htmlWriter);
   HttpContext.Current.Response.Write(stringWriter.ToString());
   HttpContext.Current.Response.Flush();
   HttpContext.Current.Response.End();
}