$kernel = $app->make(IlluminateContractsHttpKernel::class);

實例化 Kernel

在應(yīng)用進行實例化時，已經(jīng)初始化了很多的基礎(chǔ)操作，所以下面的構(gòu)造方法將會直接使用服務(wù)容器的依賴注入來解決類之間的依賴關(guān)系。

// IlluminateContractsHttpKernel 類構(gòu)造器依賴 IlluminateContractsFoundationApplication 和 IlluminateRoutingRouter，將會通過服務(wù)容器來處理依賴關(guān)系 public function __construct(Application $app, Router $router) {     $this->app = $app;      // 主要委托 $router 來處理     $this->router = $router;     // 以下均為中間件的設(shè)置     $router->middlewarePriority = $this->middlewarePriority;      foreach ($this->middlewareGroups as $key => $middleware) {         $router->middlewareGroup($key, $middleware);     }      foreach ($this->routeMiddleware as $key => $middleware) {         $router->aliasMiddleware($key, $middleware);     } }  IlluminateContractsFoundationApplication 的處理： make 時通過別名方式直接調(diào)用 $this->instances['app']  IlluminateRoutingRouter 的處理: make 時通過別名方式直接調(diào)用 $this->bindings['router'] 數(shù)組里面 concrete 對應(yīng)的匿名函數(shù) Router 依賴 IlluminateContractsEventsDispatcher 和 IlluminateContainerContainer public function __construct(Dispatcher $events, Container $container = null) {     $this->events = $events;     $this->routes = new RouteCollection;     $this->container = $container ?: new Container; }  IlluminateContractsEventsDispatcher 的處理： make 時通過別名方式直接調(diào)用 $this->bindings['events'] 數(shù)組里面 concrete 對應(yīng)的匿名函數(shù) Dispatcher 依賴 IlluminateContractsContainerContainer public function __construct(ContainerContract $container = null) {     $this->container = $container ?: new Container; }  IlluminateContainerContainer 的處理: make 時直接調(diào)用 $this->instances['IlluminateContainerContainer'] = Object(app) IlluminateContractsContainerContainer 的處理: make 時調(diào)用別名直接調(diào)用 $this->instances['app'] = Object(app) 上面兩個一樣，沒有區(qū)別

注意：以上所列出的依賴關(guān)系，都直接委托給服務(wù)容器進行自動處理了，不需要怕怕

對 $this->bindings['router'] 和 $this->bindings['events'] 綁定事件的處理，make 時將會直接調(diào)用數(shù)組鍵 concrete 對應(yīng)的匿名函數(shù)。

make 時使用到的代碼片段

############################################## if ($concrete instanceof Closure) {                 return $concrete($this, end($this->with));  } ###############################################  $this->bindings['router'] = [         'concrete' => function ($app) {                             return new Router($app['events'], $app);                         },         'shared' => 'true',     ]; $router = new Router($app['events'], $app);  IlluminateRoutingRouter public function __construct(Dispatcher $events, Container $container = null) {     $this->events = $events;     $this->routes = new RouteCollection;     $this->container = $container ?: new Container; }

返回一個 Router 對象，同時會重置 $this->instances['router'] = $router 對象，供下次直接調(diào)用。

$this->bindings['events'] = [     'concrete' => function ($app) {             return (new Dispatcher($app))->setQueueResolver(function () use ($app) {                 return $app->make(QueueFactoryContract::class);             });             }     'shared' => 'true', ];  $dispatcher = (new IlluminateEventsDispatcher($app))->setQueueResolver(function () use ($app) {                 return $app->make(QueueFactoryContract::class);             });  IlluminateEventsDispatcher: public function __construct(ContainerContract $container = null) {     $this->container = $container ?: new Container; } public function setQueueResolver(callable $resolver) {     $this->queueResolver = $resolver;      return $this; }

返回一個 Dispatcher 對象，同時會重置 $this->instances['events'] = $dispatcher 對象，供下次直接調(diào)用。

注意：
kernel對象是融合了應(yīng)用和路由的對象，路由又注入了IlluminateEventsDispatcher對象，此為核心對象。