1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:
35:
36:
37:
38:
39:
40:
41:
42:
43:
44:
45:
46:
47:
48:
49:

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Label1: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private-Deklarationen }
    FTimer: TTimer;
    FString: string;
    procedure DoOnTimer(Sender: TObject);
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  FTimer := TTimer.Create(Self);
  FTimer.Interval := 1500;
  FTimer.OnTimer := DoOnTimer;
end;

procedure TForm1.DoOnTimer(Sender: TObject);
begin
  FString := FString + 'A';
  Label1.Caption := FString;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  FTimer.Free;
end;

end.