问谁有聊天用的Listview渲染器？

EN

<!-- Previous Implementation -->

        <ListView x:Name="MessagesListView"
              Grid.Row="0"
              BackgroundColor="Transparent"
              HasUnevenRows="True"
              ItemTemplate="{StaticResource MessageTemplateSelector}"
              ItemsSource="{Binding Messages}"
              SelectionMode="None"
              SeparatorVisibility="None" />

<!-- Remaining Implementation -->

// Previous Implmentation

    /// <summary>
    /// Override of OnAppearing method. Fires as page is appearing.
    /// Good place to set up event handlers.
    /// </summary>
    protected override void OnAppearing()
    {
        base.OnAppearing();

        ((INotifyCollectionChanged)MessagesListView.ItemsSource).CollectionChanged += OnListViewCollectionChanged;
    }

    /// <summary>
    /// Override of OnDisappearing method. Fires as page is disappearing.
    /// Good place to tear down event handlers.
    /// </summary>
    protected override void OnDisappearing()
    {
        base.OnDisappearing();

        ((INotifyCollectionChanged)MessagesListView.ItemsSource).CollectionChanged -= OnListViewCollectionChanged;
    }

    /// <summary>
    /// Scrolls a the messages listview to the last item whenever
    /// a new message is added to the collection.
    /// </summary>
    private void OnListViewCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        var myList = ((IEnumerable<Message>)MessagesListView.ItemsSource).ToList();

        // Must be ran on main thread or Android chokes.
        Device.BeginInvokeOnMainThread(async () =>
        {
            // For some reason Android requires a small delay or the scroll never happens.
            await Task.Delay(50);
            MessagesListView.ScrollTo(myList.Last(), ScrollToPosition.End, false);
        });
    }

// Remaining Implementation

Device.BeginInvokeOnMainThread (() => {
           Listviewname.scrollto(items[count-1], scrolltoposition.end, false)
       });
 });