[ART]

Ребят, подскажи как сделать свою коллекцию со вставкой, добавление и удалением. Прост никогда не работал с коллекциями.

Код:

type
  TTrack = class(TCollectionItem)
   private
    FId: integer;
    FOwner: integer;
    FTitle: string;
    FArtist: string;
    FUrl: string;
    FDuration: integer;
   public
    property Id: integer read FId write FId;
    property Owner: Integer read FOwner write FOwner;
    property Title: string read FTitle write FTitle;
    property Artist: string read FArtist write FArtist;
    property Url: string read FUrl write FUrl;
    property Duration: integer read FDuration write FDuration;
    constructor create(Collection: TCollection); override;
    destructor  destroy; override;
  end;

  TTrackList = class(TCollection)
  private
   function GetItem(Index: Integer): TTrack;
   procedure SetItem(Index: integer; const Value: TTrack);
  public
   function Add: TTrack;
   function Insert(Index: Integer; value: TTrack): TTrack;
   procedure Delete(Index: Integer);
   property Item[Index: Integer]: TTrack read GetItem write SetItem; default;
  end;

constructor TTrack.create(Collection: TCollection);
begin
  inherited Create(Collection);
 FTitle    := '';
 FArtist   := '';
 FUrl      := '';
 FDuration := 0;
 FId       := 0;
 FOwner    := 0;
end;

destructor TTrack.destroy;
begin
 FTitle  := '';
 FArtist := '';
 FUrl    := '';
 FDuration := 0;
 FId       := 0;
 FOwner    := 0;
 inherited destroy;
end;

function TTrackList.Add: TTrack;
begin
  result := TTrack(inherited Add);
  {Result.Id       := id;
  Result.Owner    := owner;
  Result.Title    := title;
  Result.Artist   := artist;
  Result.Url      := url;
  Result.Duration := duration; }
end;

function TTrackList.GetItem(Index: Integer): TTrack;
begin
  result := inherited Items[Index] as TTrack;
end;

procedure TTrackList.SetItem(Index: Integer; const Value: TTrack);
begin
  inherited SetItem(index, value);
end;

{procedure TTrackList.Insert(Index: Integer; value: TTrack);
begin
  result := inherited Insert(Index, value);
end; }

procedure TTrackList.Delete(Index: Integer);
begin
 inherited Delete(Index);
end;

Код:

procedure TForm1.Button1Click(Sender: TObject);
var
 Tracks: TTrackList;
 Track: TTrack;
 i: integer;
begin
  Tracks := TTrackList.Create(nil);
  for i := 0 to 5 do begin
   Track := Tracks.Add; //ошибка вылетает при добавлении
   Track.Id := Random(100);
  end;

  for i := 0 to 5 do begin
   ListBox1.Items.Add(IntToStr(Tracks.Item[i].Id));
  end;

end;

Причем в разных источниках по разному, но у меня все равно не работает