public string ToString(User user, IApiProvider site) { if (Pages.Count > 0 && Pages.Last().Rows.Last().Buttons.Last().Executor != "page previous") { AddPage(); Pages.RemoveAt(Pages.Count - 1); } if (PageIndex > Pages.Count - 1 || PageIndex < 0) { return(null); } user.KeyboardPage = PageIndex; user.Keyboard = Pages; return(site.BuildKeyboard(Pages[PageIndex]).ToString()); }