显示错误的Symfony KnpMenuBundle [MenuBuilder作为服务]

Question

我使用sumfony 3.3.10，我安装了一个新的symfony项目，并使用以下命令添加了knpMenuBundle，

composer require knplabs/knp-menu-bundle "^2.0"

现在，我完全按照这里提到的那样跟踪了一切，service.html

并在default/index.html.twig文件中添加了这一行{{ knp_menu_render('main') }}。

现在，当我执行这个项目时，它会显示出这个错误，

[InvalidArgumentException]


Menu builder services must be public but "app.menu_builder" is a private service.

config.yml

knp_menu:
        # use "twig: false" to disable the Twig extension and the TwigRenderer
        twig:
            template: KnpMenuBundle::menu.html.twig
        #  if true, enables the helper   for PHP templates
        templating: false
        # the renderer to use, list is also available by default
        default_renderer: twig

MenuBuilder.php

    <?php
namespace AppBundle\Menu;

use Knp\Menu\FactoryInterface;

    class MenuBuilder
{
    private $factory;

    /**
     * @param FactoryInterface $factory
     *
     * Add any other dependency you need
     */
    public function __construct(FactoryInterface $factory)
    {
        $this->factory = $factory;
    }

    public function createMainMenu(array $options)
     {
        $menu = $this->factory->createItem('root');

        $menu->addChild('Home', array('route' => 'homepage'));
        // ... add more children

        return $menu;
     }
 }

services.yml

app.menu_builder:
            class: AppBundle\Menu\MenuBuilder
            arguments: ["@knp_menu.factory"]
            tags:
                - { name: knp_menu.menu_builder, method: createMainMenu, alias: main } # The alias is what is used to retrieve the menu

我该怎么解决这个问题。任何帮助都是非常感谢的。谢谢

Answer 1

我将public: true添加到services.php中的app.menu_builder服务中，

app.menu_builder:
        class: AppBundle\Menu\MenuBuilder
        public: true
        arguments: ["@knp_menu.factory"]
        tags:
            - { name: knp_menu.menu_builder, method: createMainMenu, alias: main } # The alias is what is used to retrieve the menu

现在一切都很好。

参考：private.html#marking-services-as-public-private