如何使用MVVM过滤C# UWP中的异步列表？

// Model
public class Item
{
    public string Name { get; set; }
    // Other properties
}

// ViewModel
public class MainViewModel : INotifyPropertyChanged
{
    private ObservableCollection<Item> items;
    private string filter;

    public ObservableCollection<Item> Items
    {
        get { return items; }
        set
        {
            items = value;
            OnPropertyChanged(nameof(Items));
        }
    }

    public string Filter
    {
        get { return filter; }
        set
        {
            filter = value;
            FilterItems();
            OnPropertyChanged(nameof(Filter));
        }
    }

    public MainViewModel()
    {
        // Initialize items collection
        Items = new ObservableCollection<Item>();
        // Load items asynchronously
        LoadItemsAsync();
    }

    private async void LoadItemsAsync()
    {
        // Load items from data source asynchronously
        // For example, using a web service or a database
        // Assign the loaded items to the Items property
        Items = await LoadItemsFromDataSourceAsync();
    }

    private void FilterItems()
    {
        // Apply filter logic to the Items collection
        // For example, using LINQ query
        var filteredItems = Items.Where(item => item.Name.Contains(Filter)).ToList();
        // Update the filtered items collection
        // You can create a new ObservableCollection or clear and add items to the existing one
        // For simplicity, let's assume we have a FilteredItems property
        FilteredItems = new ObservableCollection<Item>(filteredItems);
    }

    // Other methods and properties

    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

// View
<Page>
    <Grid>
        <TextBox Text="{Binding Filter, Mode=TwoWay}" />
        <ListView ItemsSource="{Binding FilteredItems}">
            <!-- Define item template -->
        </ListView>
    </Grid>
</Page>