type
  TMyThreads = class(TThread)
  private
    procedure UpDate;
  protected
    procedure Execute; override;
  public
    Ergebnis: Real;
    Zaehl, Reps : Integer;
  end;

  TForm1 = class(TForm)
    Button1: TButton;
    Memo1: TMemo;
    Button2: TButton;
    Button3: TButton;
    Label1: TLabel;
    Edit1: TEdit;
    ProgressBar1: TProgressBar;
    Label2: TLabel;
    Label3: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private-Deklarationen }
    ThreadArray: array of TMyThreads;
  public
    { Public-Deklarationen }
procedure Update(Durchlauf,Reps : Integer; Ergebn: Real);
  end;

var
  Form1: TForm1;
  Reps : Integer;
  StartZeit : TTime;
  Prozent : Real;

implementation

{$R *.dfm}

procedure TMyThreads.Execute;
var
  Loop : Integer;
begin
  for Loop := 1 to Reps do
  begin
    Ergebnis := Ergebnis + 1/Loop;
    Zaehl := Loop;
    Synchronize(Update);
  end;
  Application.MessageBox('Fertig!','Info', 0+64);
  Destroy;
end;

procedure TMyThreads.UpDate;
begin
  Form1.Update(Zaehl, Reps, Ergebnis);
end;

procedure TForm1.Update(Durchlauf,Reps : Integer; Ergebn: Real);
var aktZeit, GesZeit : TTime;
begin
  Memo1.Lines.Add(FloatToStr(Ergebn));
  Label1.Caption := 'Durchlauf: ' + IntToStr(Durchlauf);
  ProgressBAr1.Position := Durchlauf;
  aktZeit := Now;
  GesZeit := aktZeit-StartZeit;
  Label2.Caption := TimeToStr(geszeit);
  Prozent := 100 / (Reps / Durchlauf);
  Label3.Caption := FormatFloat('0%',Prozent);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
StartZeit := Now;
Reps := StrToInt(Edit1.Text);
ProgressBar1.Max := Reps;
  Setlength(ThreadArray, 1);

    ThreadArray[1] := TMyThreads.Create(True);
    ThreadArray[1].Ergebnis := 0;
    ThreadArray[1].Reps := Reps;

    ThreadArray[1].Resume;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
if ThreadArray[1].Suspended then
  ThreadArray[1].Resume
else
  ThreadArray[1].Suspend;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
Memo1.DoubleBuffered := true;
Form1.Doublebuffered := true;
end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
//ThreadArray[0].Terminate;
end;

end.