protected virtual void ApplySortCore(PropertyDescriptor property, ListSortDirection direction)
    {
        this.SortProperty = property;
        this.SortDirection = direction;
        if (direction == ListSortDirection.Ascending)
        {
            ResetItems(this.OrderBy(item => property.GetValue(item)).ToList());
            IsSorted = true;
            OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, property));
        }
        else if (direction == ListSortDirection.Descending)
        {
            ResetItems(this.OrderByDescending(item => property.GetValue(item)).ToList());
            IsSorted = true;
            OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, property));
        }
    }

private void ResetItems(List<TItem> items)
    {
        base.ClearItems();

        foreach (var item in items)
        {
            base.InsertItem(IndexOf(item), item);
        }
    }

protected virtual void ApplySortCore(PropertyDescriptor property, ListSortDirection direction)
{
    this.SortProperty = property;
    this.SortDirection = direction;

    IEnumerable<T> items = null;
    if (direction == ListSortDirection.Ascending)
    {
        items = this.OrderBy(item => property.GetValue(item));
    }
    else
    {
        items = this.OrderByDescending(item => property.GetValue(item));
    }

    ResetItems(items.ToList ());

    IsSorted = true;
    OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, property));
}

private void ResetItems(IEnumerbale<TItem> items)
{
    base.ClearItems();

    foreach (var item in items)
    {
        base.Add(item);
    }
}