private void OnSelectionChanged(object sender, SelectionChangedEventArgs args)
{
if (BindableSelectedItems == null)
return;
foreach (var item in args.RemovedItems)
{
if (BindableSelectedItems.Contains(item))
BindableSelectedItems.Remove(item);
}
foreach (var item in args.AddedItems)
{
if (!BindableSelectedItems.Contains(item))
{
var index = SelectedItems.IndexOf(item);
BindableSelectedItems.Insert(index, item);
}
}
}