cannot perform this operation on a closed dataset

谁能告诉我如何找到啊？
这一操作不适用于封闭的数据库！！
procedure  tfrm_bridge_gateway.myupdate;
  var
  ur:userarray;
  i,n:Integer;
begin
   if frm_main.ClientSocket1.Active then
   begin      ADODataSet_gateway.CreateDataSet;
      ADODataSet_gateway.savetoFile('.\data\bridge.Dat');      text:='';
      n:=0;
      frm_main.ClientSocket1.Socket.SendText('#'+'6');
      while  text=''  do
         begin
         text:=frm_main.ClientSocket1.Socket.ReceiveText;
         end;
     while (text<>'end') and frm_main.ClientSocket1.Active  do
     begin        ur:=split(text,'|');
      
         with ADODataSet_bridge do
         begin
           i:=0;
           Append;
           for i:=1 to 255 do
              begin
              if length(ur[i])=0 then break;
              Fields[i].AsString:=ur[i];
              end;
           post;
           end;
         frm_main.ClientSocket1.Socket.SendText('null');
         text:='';
         while  text=''  do
         begin
           text:=frm_main.ClientSocket1.Socket.ReceiveText;
         end;
      end;
     ADODataSet_bridge.savetoFile('.\data\bridge.Dat');
     ADODataset_bridge.Close;
     end;
end;