如何获取Xamarin CollectionView项目的索引？

collectionView.ItemSelected += (sender, e) =>
{
    if (e.SelectedItem != null)
    {
        var index = collectionView.ItemsSource.IndexOf(e.SelectedItem);
        // 使用索引进行后续操作
    }
};

// ViewModel中的属性
private int selectedIndex;
public int SelectedIndex
{
    get { return selectedIndex; }
    set { selectedIndex = value; OnPropertyChanged(); }
}

// XAML中的绑定
<CollectionView SelectedItem="{Binding SelectedIndex}" ... />

var longPressGestureRecognizer = new LongPressGestureRecognizer();
longPressGestureRecognizer.Command = new Command((obj) =>
{
    var position = longPressGestureRecognizer.GetTouchPoints(collectionView).FirstOrDefault();
    var index = collectionView.GetIndexPathForItemAtPoint(position)?.Row;
    // 使用索引进行后续操作
});
collectionView.GestureRecognizers.Add(longPressGestureRecognizer);