将实体传递给Symfony4中的createForm方法

createForm(FormTypeInterface $type, $data = null, array $options = [])

use App\Entity\User;
use App\Form\UserType;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Routing\Annotation\Route;

class UserController extends AbstractController
{
    /**
     * @Route("/user/create", name="user_create")
     */
    public function createUser(Request $request)
    {
        // 创建实体对象
        $user = new User();

        // 创建表单
        $form = $this->createForm(UserType::class, $user);

        // 处理表单提交
        $form->handleRequest($request);
        if ($form->isSubmitted() && $form->isValid()) {
            // 处理表单数据
            $entityManager = $this->getDoctrine()->getManager();
            $entityManager->persist($user);
            $entityManager->flush();

            // 重定向到成功页面
            return $this->redirectToRoute('success');
        }

        // 渲染表单模板
        return $this->render('user/create.html.twig', [
            'form' => $form->createView(),
        ]);
    }
}