memo1.Lines.Add(''Create newspaper object successed!'');
      memo1.Lines.Add(''read : '' + Info + '' return code : '' + inttostr(i));
    finally
      FreeMem(Info);
      NewspaperObj.Free;
    end;
  end;
end;
// interface方法示例
procedure TfmMain.btnUseInterfaceClick(Sender: TObject);
var
  CircleObj: ICircle;
  Info: pchar;
  i: integer;
begin
  CircleObj := GetCircle;
  if CircleObj = nil then
    memo1.Lines.Add(''Create circle object failed!'')
  else
  begin
    try
      GetMem(Info, 255);
      i := CircleObj.Scroll(Info);
      memo1.Lines.Add(''Create circle object successed!'');
      memo1.Lines.Add(''scroll : '' + Info + '' return code : '' + inttostr(i));
    finally
      FreeMem(Info);
      CircleObj := nil;
    end;
  end;
end;
// class reference方法示例
procedure TfmMain.btnUseReferenceClick(Sender: TObject);
var
  BallObj : TIBall;
  Info: pchar;
  i: integer;
begin
  BallObj := GetBall.Create;
  if BallObj = nil then
    memo1.Lines.Add(''Create ball object failed!'')
  else
  begin
    try
      GetMem(Info, 255);
      i := BallObj.Play(Info);
      memo1.Lines.Add(''Create ball object successed!'');
      memo1.Lines.Add(''play : '' + Info + '' return code : '' + inttostr(i));
    finally
      FreeMem(Info);
      BallObj.Free;
    end;
  end;
end;
// .inc文件方法示例
procedure TfmMain.btnUseIncClick(Sender: TObject);
var
  CarObj : TCar;
  Info: pchar;
  i: integer;
begin
  CarObj := GetCar.Create;
  if CarObj = nil then
    memo1.Lines.Add(''Create car object failed!'')
  else
  begin
    try
      GetMem(Info, 255);
      i := CarObj.Run(Info);
      memo1.Lines.Add(''Create car object successed!'');
      memo1.Lines.Add(''car : '' + Info + '' return code : '' + inttostr(i));
    finally
      FreeMem(Info);
      CarObj.Free;
    end;
  end;
end;
end.
 
UnitPublic.pas源代码：
unit UnitPublic;
interface
type
// ----- virtual, abstract的类定义 -----
  TPaper = class(TObject);
  TNewspaper = class(TPaper)
  public
    function Read(info : pchar) : integer; virtual; abstract;
  end;
implementation
end.
 
UnitIDest.pas源代码：
unit UnitIDest;
interface
type
  ICircle = interface
  [''{A971