CustomFileListT Class

public override int Compare(object x, object y)
{
    ShellListBaseItem item1 = x as ShellListBaseItem;
    ShellListBaseItem item2 = y as ShellListBaseItem;
    if (item1 == null || item2 == null)
        return 0;
    if (!SortColumnShellID.IsCustomId())
    {
        // the shell is asked
        ShellBrowser.SpecialFolder = ShellFolder.Desktop;
        if (Sorting == SortOrder.Ascending)
            return ShellBrowser.CompareIDs(item1.RelativeItemIdList, item2.RelativeItemIdList, m_SortColumnShellIndex);
        else
            return ShellBrowser.CompareIDs(item2.RelativeItemIdList, item1.RelativeItemIdList, m_SortColumnShellIndex);
    }
    else
    {
        // perform a normal alphanumeric compare
        if (Sorting == SortOrder.Ascending)
            return item1.SubItems[SortColumn].Text.CompareTo(item2.SubItems[SortColumn].Text);
        else
            return item2.SubItems[SortColumn].Text.CompareTo(item1.SubItems[SortColumn].Text);
    }
}