unit Unit1;

interface

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

type
mybutton=class(tbutton)
    constructor Create(AOwner: TComponent); override;
    procedure CreateParams(var Params: TCreateParams); override;
end;

  TForm1 = class(TForm)
    Button2: TButton;
    procedure Button2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    a: mybutton;
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}
constructor myButton.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  ControlStyle := [csSetCaption, csOpaque, csDoubleClicks];
  Width :=  75 ;
  Height :=  25 ;
  TabStop := True;
end;

procedure myButton.CreateParams(var Params: TCreateParams);
const
  ButtonStyles: array[Boolean] of DWORD = (BS_PUSHBUTTON, BS_DEFPUSHBUTTON);
begin
  inherited CreateParams(Params);
  CreateSubClass(Params, 'BUTTON');
  Params.Style := Params.Style or ButtonStyles[True];
  Params.Style := Params.Style or BS_MULTILINE	;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  a.caption:='aaaaaaaaa'+'bbbbbbbbbbbbbb';
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  a:=mybutton.Create(form1);
  a.parent:=form1;
  a.height:= 50 ;
  a.caption:='aaaaaaaaa';
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  a.destroy;
end;

end.