اود انشآء او التعديل على ال Listbox ؟

PHP كود :

unit AListBox;

interface

uses
  SysUtils, Classes, Controls, StdCtrls;

type
  TAListBox = class(TListBox)
  private
  FItems : TCollection;
    { Private declarations }
  protected
    { Protected declarations }
  public
    { Public declarations }
  published
    { Published declarations }
   Property Items : TCollection Read FItems Write FItems; //
  end;

  TAListBoxItem = class(TCollectionItem)
  private
  FCaption: String;  { Private declarations }
  protected
    { Protected declarations }
  public
    { Public declarations }
  published
    { Published declarations }
  Property Caption : String Read FCaption Write FCaption;
  end;

procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('AListBox', [TAListBox]);
end;

end.

كود :

unit AListBox;

interface

uses
  SysUtils, Classes, Controls, StdCtrls;

type
  TAListBoxItem = class; //<-- here
  TAListBoxItems = class; // <-- here
  TAListBox = class(TListBox)
  private
    { Private declarations }
  FItems: TAListBoxItems;
  procedure SetItems(Items: TAListBoxItems);
  protected
    { Protected declarations }
  public
    { Public declarations }
    constructor Create(aOwner: TComponent); override;
    destructor Destroy(); override;
  published
    { Published declarations }
   Property Items : TAListBoxItems Read FItems Write SetItems;
  end;
//----> added
  TAListBoxItem = class(TCollectionItem)
  private
  { Private declarations }
  FCaption: String;
  // from here u can add what u want ...!
  protected
    { Protected declarations }
  public
    { Public declarations }
    constructor Create(collection: TCollection); override;
  published
    { Published declarations }
  Property Caption : String Read FCaption Write FCaption;
  end;
// --->  added
  TAListBoxItems = class(TCollection)
  private
    FManager: TAListBox;
  protected
    function GetOwner(): TPersistent; override;
  public
    constructor Create(manager: TAListBox);
  end;

procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('Standard', [TAListBox]);
end;

{ TAListBox }


{ TAListBoxItem }

constructor TAListBoxItem.Create(collection: TCollection);
begin
inherited Create(collection);
FCaption :='';
end;

{ TAListBoxItems }

constructor TAListBoxItems.Create(manager: TAListBox);
begin
 inherited Create(TAListBoxItem);
  FManager := manager;
end;

function TAListBoxItems.GetOwner: TPersistent;
begin
result := FManager;
end;

{ TAListBox }

constructor TAListBox.Create(aOwner: TComponent);
begin
 inherited Create(aOwner);
 FItems := TAListBoxItems.Create(self);
end;

destructor TAListBox.Destroy;
begin

  FItems.Free();
  inherited Destroy();
end;

procedure TAListBox.SetItems(Items: TAListBoxItems);
begin
FItems.Assign(Items);
end;

end.