A:

unit MyEds;

interface

uses
  SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
  Forms, Dialogs, StdCtrls;

type
  TPropertyEditor = class(TButton)
  private
    { Private declarations }
    FStringStuff: TStrings;
  protected
    { Protected declarations }
  public
    { Public declarations }
    constructor create(Aowner: TComponent); override;
    destructor destroy; override;
    procedure SetStrings(s: TStrings);
  published
    { Published declarations }
    property StringStuff: TStrings read FStringStuff write SetStrings;
  end;

procedure Register;

implementation

constructor TPropertyEditor.create(AOwner: TComponent);
begin
  inherited create(AOwner);
  FStringStuff := TStringList.create;
end;

destructor TPropertyEditor.destroy;
begin
  FStringStuff.free; {Plugs the memory leak.}
  inherited destroy;
end;

procedure TPropertyEditor.SetStrings(s: TStrings);
begin
  if FStringStuff <> s then {This conditional is optional.}
    FStringStuff.Assign(s);
end;

procedure Register;
begin
  RegisterComponents('Lloyd', [TPropertyEditor]);
end;

end.