响应的是OnEnter事件:
procedure TForm1.ComboBox1Enter(Sender: TObject);
begin
  if not (Self.ComboBox1.Items.Count>0)
  then with Self.Query1 do
       begin
         Close;
         SQL.Clear;
         Params.Clear;
         SQL.Add('select work_order_number from data0006 order by work_order_number');
         Open;
         First;
         Self.ComboBox1.Items.Clear;
         if RecordCount>0
         then while not Eof do
              begin
                Self.ComboBox1.Items.Add(Fields.Fields[0].AsString);
                Next;
              end;
         Close;
       end;
end;
为什么这个值work_order_number取不得啊?????