ShowAs stripe for calendar control template.

Wino.Calendar.ViewModels/CalendarPageViewModel.cs

@@ -115,6 +115,7 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(IsEventDetailsVisible))]
     [NotifyCanExecuteChangedFor(nameof(JoinOnlineCommand))]
+    [NotifyPropertyChangedFor(nameof(CanJoinOnline))]
     public partial CalendarItemViewModel DisplayDetailsCalendarItemViewModel { get; set; }
 
     public bool IsEventDetailsVisible => DisplayDetailsCalendarItemViewModel != null;
@@ -227,12 +228,6 @@ public partial class CalendarPageViewModel : CalendarBaseViewModel,
         };
     }
 
-    public override void OnNavigatedFrom(NavigationMode mode, object parameters)
-    {
-        // Do not call base method because that will unregister messenger recipient.
-        // This is a singleton view model and should not be unregistered.
-    }
-
     public override void OnNavigatedTo(NavigationMode mode, object parameters)
     {
         base.OnNavigatedTo(mode, parameters);