如何在Symfony 3中上传文件

// src/AppBundle/Form/FileType.php

namespace AppBundle\Form;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\Extension\Core\Type\FileType as SymfonyFileType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;

class FileType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('file', SymfonyFileType::class, [
                'label' => 'Choose file',
            ]);
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults([
            'data_class' => 'AppBundle\Entity\File',
        ]);
    }
}

// src/AppBundle/Controller/FileController.php

namespace AppBundle\Controller;

use AppBundle\Entity\File;
use AppBundle\Form\FileType;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Routing\Annotation\Route;

class FileController extends Controller
{
    /**
     * @Route("/upload", name="file_upload")
     */
    public function uploadAction(Request $request)
    {
        $file = new File();
        $form = $this->createForm(FileType::class, $file);
        $form->handleRequest($request);

        if ($form->isSubmitted() && $form->isValid()) {
            $uploadedFile = $file->getFile();

            // 处理文件上传
            $fileName = md5(uniqid()).'.'.$uploadedFile->guessExtension();
            $uploadedFile->move(
                $this->getParameter('file_directory'),
                $fileName
            );

            // 其他逻辑...

            return $this->redirectToRoute('file_success');
        }

        return $this->render('file/upload.html.twig', [
            'form' => $form->createView(),
        ]);
    }
}

# app/config/config.yml

parameters:
    file_directory: '%kernel.project_dir%/web/uploads/files'

{# app/Resources/views/file/upload.html.twig #}

{% extends 'base.html.twig' %}

{% block body %}
    <h1>Upload File</h1>

    {{ form_start(form) }}
        {{ form_widget(form) }}
        <button type="submit">Upload</button>
    {{ form_end(form) }}
{% endblock %}