unit InterfaceSpaszUnit;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  IMyIF = Interface(IInterface)
    function GetLength(i: Integer): Integer;
  end;

  TMyExample = class(TInterfacedObject, IMyIF)
  private
    FEinFeld: array of array of Integer;
  public
    constructor Create(); overload;
    function GetLength(i: Integer): Integer;
  end;

  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private-Deklarationen }
    MyExample: TMyExample;
    function GetWert(bsp: IMyIF): String;
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

{ TMyExample }
constructor TMyExample.Create;
var
  i: Integer;
begin
  inherited Create;
  SetLength(FEinFeld, 2);
  for i := 0 to Length(FEinFeld) - 1 do
    SetLength(FEinFeld[i], i);
end;

function TMyExample.GetLength(i: Integer): Integer;
begin
  Result := Length(FEinFeld[i]);
end;

{ TForm1 }
procedure TForm1.FormCreate(Sender: TObject);
begin
  MyExample := TMyExample.Create;
end;

function TForm1.GetWert(bsp: IMyIF): String;
begin
  Result := IntToStr(bsp.GetLength(1));
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  ShowMessage(GetWert(MyExample));
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  Close;
end;
end.