delphi TFile写入文本

//需要引用System.IOUtils单元
procedure TForm7.Button3Click(Sender: TObject);
var
  sFileName: string;
  tstream: TStreamWriter;
begin
  Memo1.Clear;
  Memo1.Lines.Add(TPath.GetFileName(Application.ExeName));
  Memo1.Lines.Add(TPath.GetDownloadsPath);
  Memo1.Lines.Add(TPath.GetHomePath);

  sFileName := TDirectory.GetCurrentDirectory + '\' + '33333.txt';

  if TFile.Exists(sFileName) then
    TFile.Delete(sFileName);

  tstream := TFile.CreateText(sFileName);
  try
    tstream.WriteLine('33333333333');
    tstream.WriteLine('GBK中文显示不知道有没有问题！');
  finally
    tstream.Free;
  end;

end;