ListViewの要素を動的に増したい場合はどうする？

FlexibleListView.cs

var listItems = new ObservableCollection<CellItems>();
foreach (var i in Enumerable.Range(0, 10))
{
    listItems.Add(new CellItems { StringItem = "StringItem-" + i });
}

var list = new ListView
{
    HasUnevenRows = true,
    ItemsSource = listItems,
    ItemTemplate = new DataTemplate(typeof(FlexibleCell)),
};

var button = new Button { Text = "Change List" };
button.Clicked += (sender, e) =>
{
    listItems.Add(new CellItems { StringItem = "NewStringItem", AdditionlItem = "AdditionalItem" });
};

~~~~~~~~~~~~~~~~~~~~

public FlexibleCell() {
  var stringItem = new Label();
  stringItem.SetBinding(Label.TextProperty, "StringItem");

  var additionalItem = new Label();
  additionalItem.SetBinding(Label.TextProperty, "AdditionalItem");

  View = new StackLayout
  {
      Orientation = StackOrientation.Horizontal,
      Children =
      {
          stringItem,
          additionalItem,
      },
  };
}