Probleme mit BlockRead / BlockWrite

[Luckie]

Delphi-Quellcode:

var
  f: File;
  cntWritten: Integer;
  cntRead: Integer;
  buffer: Array of Byte;
  s: string = 'Mein Text.';

begin
  AssignFile(f, 'd:\test.txt');
  {$I-}
  Rewrite(f);
  if IOResult = 0 then
  begin
    BlockWrite(f, s[1], Length(s), cntWritten);
    ShowMessage('Geschrieben Bytes: '+IntToStr(cntWritten));
    CloseFile(f);
  end
  else
    ShowMessage(SysErrorMessage(GetLastError));
  {$I+}

  AssignFile(f, 'd:\test.txt');
  {$I-}
  Reset(f);
  if IOResult = 0 then
  begin
    SetLength(buffer, Length(s));
    BlockRead(f, buffer[0], Length(s), cntRead);
    ShowMessage('Gelesener Text: ' + string(buffer) + '. Gelesene Bytes: ' + IntToStr(cntRead));
    CloseFile(f);
  end
  else
    ShowMessage(SysErrorMessage(GetLastError));
  {$I+}
end.

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