Memo Bricht in Lines um

[TomyN]

Wenn dem so ist, warum passiert dann mit diesem Code

Code:

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.ExtCtrls, Vcl.StdCtrls;

type
  TForm1 = class(TForm)
    Memo1: TMemo;
    Timer1: TTimer;
    procedure FormCreate(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private-Deklarationen }
    lineIndex: Integer;
    //theList:   TStringList;
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  Memo1.lines.Add('The first line is a long line. Let us see what will happen');
  lineIndex:= Memo1.Lines.Add('This is the line of interest');
  Memo1.Lines.Add('******END******');
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  memo1.Lines[lineIndex]:= IntToHex(Random($1000),4) + ' New Text for the Test. Good Luck';
end;

end.

Das hier: https://www.youtube.com/watch?v=Cgy8GVSaJUc