gridview输出流excel

  this.DataGrid1.Page.EnableViewState   =   false;
  System.IO.StringWriter     tw       =   new   System.IO.StringWriter();
  System.Web.UI.HtmlTextWriter   hw     =   new   System.Web.UI.HtmlTextWriter(tw);
  this.DataGrid1.RenderControl(hw);
  string   HtmlInfo   =   tw.ToString().Trim();

  string   DocFileName   =   "审批信息.xls ";
  string   FilePathName   =   Request.PhysicalPath;
  FilePathName     =   FilePathName.Substring(0,FilePathName.LastIndexOf( "\\ "));
  //得到Excel文件的物理地址
  FilePathName     =   FilePathName   + "\\ "   +   DocFileName;
  System.IO.File.Delete(FilePathName);  
  FileStream   Fs     =   new   FileStream(FilePathName,   FileMode.Create);
  BinaryWriter   BWriter=   new   BinaryWriter(Fs,System.Text.Encoding.GetEncoding( "GB18030 "));
  //将DataGrid的信息写入Excel文件
  BWriter.Write(HtmlInfo);
  BWriter.Close();
  Fs.Close();