BaconographyPortable.ViewModel.MessagesViewModel.Messages_CollectionChanged C# (CSharp) Метод

        void Messages_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
        {
            if ((e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Add || e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Replace) &&
                e.NewItems != null && e.NewItems.Count == 1 && e.NewItems[0] is MessageViewModel)
            {
                var vm = e.NewItems[0] as MessageViewModel;
                if(vm.IsNew)
                    MaybeToastNewMessage(vm);
            }
        }