Extends ListCollectionView to provide indexer based access to CollectionViewSource sources in XAML binding.

IndexAccessibleListCollectionView.cs

    using System;
    using System.Collections;
    using System.Windows.Data;

    public class IndexAccessibleListCollectionView : ListCollectionView
    {
        public IndexAccessibleListCollectionView(IEnumerable collection)
            : base(new ArrayList())
        {
            foreach (object item in collection)
	        {
                base.InternalList.Add(item);
	        }
        }

        public object this[int index]
        {
            get
            {
                return this.GetItemAt(index);
            }
        }
    }

The current implementation will likely have many caveats, but it certainly gives us easy readonly indexer based access.

Simple set the CollectionViewType property on the CollectionViewSource.