详解Laravel框架的依赖注入功能

<?php
namespace App\Http\Controllers;
use App\User;
use App\Repositories\UserRepository;
use App\Http\Controllers\Controller;
class UserController extends Controller
{
    protected $userRepository;
    public function __construct(UserRepository $userRepository)
    {
        $this->userRepository = $userRepository;
    }
    public function show($id)
    {
        $user = $this->userRepository->find($id);
        return view('user.profile', ['user' => $user]);
    }
}

<?php
$container->bind('My\Service', function($container) {
return new My\Service($container->make('My\AnotherService'));
});

<?php
namespace App\Providers;
use Illuminate\Support\ServiceProvider;
class MyServiceProvider extends ServiceProvider
{
    public function register()
    {
        $this->app->singleton(\My\Service::class, function ($app) {
            return new \My\Service($app->make('My\AnotherService'));
        });
    }
}

<?php
namespace App\Http\Controllers;
use App\User;
use App\Http\Controllers\Controller;
class MyController extends Controller
{
    protected $myService;
    public function __construct(\My\Service $myService)
    {
        $this->myService = $myService;
    }
    // .. 方法
}

<?php
namespace App\Http\Controllers;
use App\User;
use App\Http\Controllers\Controller;
use Facebook\Facebook;
class FacebookApiAccessController extends Controller
{
    protected $facebook;
    public function __construct(Facebook\Facebook $facebook)
    {
        $this->facebook = $facebook;
    }
    //.. action methods here
}

<?php
$container->singleton('Facebook\Facebook', function() {
  return new \Facebook\Facebook([
    'app_id' => config('services.facebook.app_id'),
    'app_secret' => config('services.facebook.app_secret'),
    'default_graph_version' => 'v2.10',
  ]);
});