public function testAction() {
$request = $this->getRequest();
$form = $this->createFormBuilder()
        ->add('attachment', 'file')
        ->getForm();
    $form->handleRequest($request);

if ($form->isValid()) {
    $OriginalName = $form['attachment']->getData()->getClientOriginalName();
    $extension = $form['attachment']->getData()->guessExtension();
    $size = $form['attachment']->getData()->getClientSize();
    $error = $form['attachment']->getData()->getError();
    $valid = $form['attachment']->getData()->isValid();

    echo"<pre>";
    var_dump($OriginalName,$extension,$size,$error,$valid);
    echo"</pre>";


    $dir = "/xampp/htdocs/WebTest/uploads";
    $form['attachment']->getData()->move($dir, rand(1, 99999).'.'.$extension);
}

  return $this->render('BundleTestBundle:Test:test.html.twig', array(
      'form' => $form->createView(),
  ));

<form action="{{ path('test') }}" method="post" {{ form_enctype(form) }}>
{{ form_widget(form) }}

<input type="submit" />