无法通过Composer加载类

Question

我尝试通过以下方式更新doctrine架构：

$ php bin/console doctrine:schema:update --force

而且我一直在：

PHP Fatal error:  Uncaught 
Symfony\Component\Debug\Exception\ClassNotFoundException: Attempted to 
load class "FOSUserBundle" from namespace "App\FOS\UserBundle".

Kernel.php：

 <?php

 namespace App;

use Symfony\Bundle\FrameworkBundle\Kernel\MicroKernelTrait;
use Symfony\Component\Config\Loader\LoaderInterface;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\HttpKernel\Kernel as BaseKernel;
use Symfony\Component\Routing\RouteCollectionBuilder;

class Kernel extends BaseKernel
{
use MicroKernelTrait;

const CONFIG_EXTS = '.{php,xml,yaml,yml}';

public function getCacheDir()
{
    return $this->getProjectDir().'/var/cache/'.$this->environment;
}

public function getLogDir()
{
    return $this->getProjectDir().'/var/log';
}

public function registerBundles()
{
    $bundles = array(
        new FOS\UserBundle\FOSUserBundle(),
    );
    $contents = require $this->getProjectDir().'/config/bundles.php';
    foreach ($contents as $class => $envs) {
        if (isset($envs['all']) || isset($envs[$this->environment])) {
            yield new $class();
        }
    }
}

composer.json文件：

"autoload": {
    "psr-4": {
        "App\\": "src/",
        "FOS\\": "vendor/"
    }
},
"autoload-dev": {
    "psr-4": {
        "Tests\\": "test/"
    }

FOSUserBundle.php命名空间是：

namespace FOS\UserBundle;

并没有工作，但namaspace App工作正常。我试过了：

$ composer dump-autoload

我究竟做错了什么？它仍然在FOS之前使用App命名空间。

Answer 1

您需要添加斜杠。

$bundles = array(
    new \FOS\UserBundle\FOSUserBundle(),
);