yii2组件

    
You can also make components in YII2

Create a directory and a file same as in YII1 in frontend or backend and write below code in it

frontend/components/Controller.php

/**
 * Description of Controller
 *
 * @author mohit
 */

namespace frontend\components;
use Yii;
class Controller extends \yii\web\Controller{
    //put your code here

    public function beforeAction($action) {
        parent::beforeAction($action);
        if(true)
            return true;
        else
            return false;

    }
}
After that use it in every controller by extending this class like this-

namespace frontend\controllers;
use Yii;
use frontend\components\Controller;
class SomeController extends Controller
{
    // code
}