如何在没有第二个提交按钮的情况下让上传按钮提交文件php Symfony3

<form action="upload.php" method="post" enctype="multipart/form-data">
  <input type="file" name="fileToUpload" id="fileToUpload">
  <input type="submit" value="上传文件">
</form>

// src/AppBundle/Controller/UploadController.php

namespace AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;

class UploadController extends Controller
{
    public function uploadAction(Request $request)
    {
        if ($request->isMethod('POST')) {
            $file = $request->files->get('fileToUpload');

            // 处理文件上传逻辑
            // 可以使用Symfony3的文件上传组件或自定义逻辑来处理文件上传
        }

        // 返回响应或渲染视图
    }
}

# app/config/routing.yml

upload:
    path: /upload
    defaults: { _controller: AppBundle:Upload:upload }

// src/AppBundle/Controller/UploadController.php

use Symfony\Component\HttpFoundation\File\UploadedFile;

// ...

public function uploadAction(Request $request)
{
    if ($request->isMethod('POST')) {
        $file = $request->files->get('fileToUpload');

        if ($file instanceof UploadedFile) {
            $fileName = md5(uniqid()) . '.' . $file->guessExtension();

            // 将文件移动到指定目录
            $file->move(
                $this->getParameter('upload_directory'),
                $fileName
            );

            // 处理文件上传后的逻辑
        }
    }

    // 返回响应或渲染视图
}

# app/config/config.yml

parameters:
    upload_directory: '%kernel.root_dir%/../web/uploads'