YII容器类依赖注入

<?php
/**
* Created by PhpStorm.
* Date: 2016/5/25
* Time: 18:09
* 容器类依赖注入
*/
namespace frontend\controllers;

use yii;
use yii\web\Controller;
use yii\di\Container;//容器类依赖注入

class DependencyinjectController extends Controller{

public function actionIndex()
{
$container = new Container();
$container->set('frontend\controllers\Driver','frontend\controllers\ManDriver');
//get方法首先实例化ManDriver,再以其返回值传递给Car
$car = $container->get('frontend\controllers\Car');
$car->run();
}
}
interface Driver{
public function drive();
}
class ManDriver implements  Driver{
public function drive(){
echo "I am an old man！";
}
}
class Car{
private $driver = null;
//public function __construct(ManDriver $driver)//ManDriver 强关联，耦合太高，故使用接口
public function __construct(Driver $driver)//第20行实现接口传递 ，消除强依赖
{
$this->driver = $driver;
}
public function run()
{
$this->driver->drive();
}
}