http://www.cnblogs.com/del/archive/2007/12/10/990040.html

//排序与倒排序
{排序函数}
function DescCompareStrings(List: TStringList; Index1, Index2: Integer): Integer;
begin
  Result := -AnsiCompareText(List[Index1], List[Index2]);
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  List: TStringList;
begin
  List := TStringList.Create;

  List.Add('bbb');
  List.Add('ccc');
  List.Add('aaa');

  //未排序
  ShowMessage(List.Text);  //bbb ccc aaa

  //排序
  List.Sort;
  ShowMessage(List.Text);  //aaa bbb ccc

  //倒排序
  List.CustomSort(DescCompareStrings);  //调用排序函数
  ShowMessage(List.Text);  //ccc bbb aaa

  //假如:
  List.Sorted := True;
  List.Add('999');
  List.Add('000');
  List.Add('zzz');
  ShowMessage(List.Text);  //000 999 aaa bbb ccc zzz
end;