protected override void OnNavigatedFrom(NavigationEventArgs e) { base.OnNavigatedFrom(e); if (e.NavigationMode == NavigationMode.Back) { Collection.LocomotivesIDs.CollectionChanged -= CollectionItems_CollectionChanged; Collection.AccessoriesIDs.CollectionChanged -= CollectionItems_CollectionChanged; Collection = null; } }
protected override void OnNavigatedTo(NavigationEventArgs e) { base.OnNavigatedTo(e); if (e.NavigationMode == NavigationMode.New) { Collection = e.Parameter as EcosItemsCollection; isNew = Collection == null; if (isNew) Collection = new EcosItemsCollection(); Collection.LocomotivesIDs.CollectionChanged += CollectionItems_CollectionChanged; Collection.AccessoriesIDs.CollectionChanged += CollectionItems_CollectionChanged; SetUIVisibility(); ValidateItems(); } }