public NavigationCommand(Action action, INavigationService navigationService)
: base(action)
{
Assumes.NotNull(navigationService);
_navigationService = navigationService;
_navigationService.CanGoBackChanged += EventServices.MakeWeak(OnCanGoBackChanged, h => _navigationService.CanGoBackChanged -= h);
}
public NavigationCommand(Action action, INavigationService navigationService)
: base(action)
{
Assumes.NotNull(navigationService);
_navigationService = navigationService;
// use navigationService for the Action passed to make weak to ensure we do not root to the command via "this"
_navigationService.CanGoBackChanged += EventServices.MakeWeak(OnCanGoBackChanged, h => navigationService.CanGoBackChanged -= h);
}
public CheckoutCartCommand(ReadOnlyObservableCollection <GroceryItem> groceryItems, IEventAggregator eventAggregator)
{
Assumes.NotNull(groceryItems);
Assumes.NotNull(eventAggregator);
_groceryItems = groceryItems;
_eventAggregator = eventAggregator;
var collectionChanged = ((INotifyCollectionChanged)groceryItems);
collectionChanged.CollectionChanged += EventServices.MakeWeak(OnCollectionChanged, h => collectionChanged.CollectionChanged -= h);
}