public BaseOrderViewModel() { IsCurrentSelected = new NotifyValue <bool>(true); IsSentSelected = new NotifyValue <bool>(); IsDeletedSelected = new NotifyValue <bool>(); Begin = new NotifyValue <DateTime>(DateTime.Today.AddMonths(-3).FirstDayOfMonth()); End = new NotifyValue <DateTime>(DateTime.Today); BeginEnabled = IsSentSelected.ToValue(); EndEnabled = IsSentSelected.ToValue(); IsCurrentSelected.Subscribe(_ => NotifyOfPropertyChange("CanPrint")); IsCurrentSelected.Subscribe(_ => NotifyOfPropertyChange(nameof(CanExport))); SessionValue(Begin, "Begin"); SessionValue(End, "End"); }