我的问题与此类似https://forum.yiiframework.com/t/rbac-restrict-backend-site/82416
我试着用下面的代码来实现它，但是它不起作用。我已经升级了yii 2，我已经做了移植。如何让它工作？
角色：管理员、用户
权限：canAccess后端
用户：管理员
分配：为admin分配角色管理员和权限canAccessBackend
/backend/controllers/SiteController.php

public function beforeAction($action)
{
    if (!parent::beforeAction($action)) {
        return false;
    }
    if (Yii::$app->user->can("canAccessBackend")) { 
    } 
    else {
        throw new ForbiddenHttpException("You do not have permission to access this page.");
    }
    return true;
}

根据评论中的建议，另一个代码。它仍然不起作用。

public function beforeAction($action)
{
    if (!parent::beforeAction($action)) {
        return false;
    }

    if (Yii::$app->user->can("canAccessBackend")) { 
        return true;
    } 
    throw new ForbiddenHttpException("You do not have permission to access this page.");
}

站点控制器.php

<?php
namespace backend\controllers;

use Yii;
use yii\web\Controller;
use yii\web\ForbiddenHttpException;
use yii\filters\VerbFilter;
use yii\filters\AccessControl;
use common\models\LoginForm;

/**
 * Site controller
 */
class SiteController extends Controller
{
    /**
     * {@inheritdoc}
     */
    public function behaviors()
    {
        return [
            'access' => [
                'class' => AccessControl::className(),
                'rules' => [
                        [
                            'allow' => true,
                            'roles' => ['canAccessBackend'], //add only admin allowed
                        ],
                ],
            ],
            'verbs' => [
                'class' => VerbFilter::className(),
                'actions' => [
                    'logout' => ['post'],
                ],
            ],
        ];
    }

    public function beforeAction($action)
    {
        if (!parent::beforeAction($action)) {
            return false;
        }

        return true;
    }

    /**
     * {@inheritdoc}
     */
    public function actions()
    {
        return [
            'error' => [
                'class' => 'yii\web\ErrorAction',
            ],
        ];
    }

    /**
     * Displays homepage.
     *
     * @return string
     */
    public function actionIndex()
    {
        return $this->render('index');
    }

    /**
     * Login action.
     *
     * @return string
     */
    public function actionLogin()
    {
        $this->layout = 'login';

        if (!Yii::$app->user->isGuest) {
            return $this->goHome();
        }

        $model = new LoginForm();
        if ($model->load(Yii::$app->request->post()) && $model->login()) {
            return $this->goBack();
        } else {
            $model->password = '';

            return $this->render('login', [
                'model' => $model,
            ]);
        }
    }

    /**
     * Logout action.
     *
     * @return string
     */
    public function actionLogout()
    {
        Yii::$app->user->logout();

        return $this->goHome();
    }
}

/公共/配置/主.php

<?php
return [
    'aliases' => [
        '@bower' => '@vendor/bower-asset',
        '@npm'   => '@vendor/npm-asset',
    ],
    'vendorPath' => dirname(dirname(__DIR__)) . '/vendor',

    'modules' => [
        'admin' => [
            'class' => 'mdm\admin\Module',
        ]
    ],

    'components' => [

        'cache' => [
            'class' => 'yii\caching\FileCache',
        ],

        'authManager' => [
            'class' => 'yii\rbac\DbManager', // or use 'yii\rbac\PhpManager'
            'defaultRoles' => ['admin', 'guest'],
        ],
        'user' => [
            'identityClass' => 'mdm\admin\models\User',
            'loginUrl' => ['admin/user/login'],
        ],

    ],
];