在Symfony2控制器中获取表单值,Child不存在

Question

这是输入用户名的源代码是:

<input type="text" id="user_username" name="user[username]" >

当我尝试在控制器中获取它时,我收到此错误:

Child "username" does not exist

控制者:

//.......
if ($request->getMethod() == 'POST') {
        $form->handleRequest($request);
        $i = 0;
        $username = $form["username"]->getData();
        $user= $em->getRepository('UsersBundle:User')->findOneByUsername($username);

//.......
}

这是formType

class EleveType extends AbstractType
{
 public function buildForm(FormBuilderInterface $builder, array $options)
   {
    $builder
        ->add('user', new UserType())
        ->add('ecole')
        ->add('niveauscolaire')

    ;
}

Answer 1

更换

$username = $form["username"]->getData();

同

$username = $form["user"]["username"]->getData();