php - DI in yii2, constructor injection -

i have created interface, i'm trying inject inside controller. i'm getting following error:

argument 1 passed backend\controllers\agencycontroller::__construct() must implement interface common\service\appserviceinterface, string given

i created service folder inside common folder, added 2 files it

• appservice.php
• appserviceinterface.php

now defined dependency inside common/bootstrap.php file below:

yii::$container->set('common\service\appserviceinterface',                      'common\service\appservice'); 

afterwards tried inject inside agencycontroller placed inside backend/controllers/agencycontroller below:

namespace backend\controllers; use common\service\appserviceinterface; public function __construct(appserviceinterface $appservice) {    $this->appservice = $appservice; } 

but i'm getting error mentioned earlier.

so have change __construct method below , working fine:

public function __construct($id, $module, appserviceinterface $appservice , $config = []) {     parent::__construct($id, $module);     $this->appservice = $appservice;  }