在寫中間件時(shí)，發(fā)現(xiàn)一個(gè)比較重要問(wèn)題，那就是中間件中獲取的controller對(duì)象，不是原來(lái)的controller對(duì)象，這樣不嚴(yán)謹(jǐn)，也導(dǎo)致在__construct()中對(duì)controller修改的屬性不生效，所以需要修改幾個(gè)地方。

控制器中間件代碼通常是這樣：

if ($request->controller) {
            $controller = Container::get($request->controller); //這里獲取到的不是原來(lái)的controller對(duì)象
}

下面是分析和修改流程：

1. 查找src/Container.php中的get()方法，調(diào)試發(fā)現(xiàn)是new了一個(gè)新的實(shí)例

   public function get(string $name)
   {
       if (!isset($this->instances[$name])) {
           if (isset($this->definitions[$name])) {
               $this->instances[$name] = call_user_func($this->definitions[$name], $this);
           } else {
               if (!class_exists($name)) {
                   throw new NotFoundException("Class '$name' not found");
               }
               $this->instances[$name] = new $name(); //返回了一個(gè)新的實(shí)例，instances和definitions都不起作用
           }
       }
       return $this->instances[$name];
   }

   剛開始準(zhǔn)備改這個(gè)get()方法，但這個(gè)方法對(duì)應(yīng)接口僅提供一個(gè)$name參數(shù)，不想改動(dòng)太大，所以換個(gè)思路改make()方法，原make()方法：

   
   public function make(string $name, array $constructor = [])
   {
       if (!class_exists($name)) {
           throw new NotFoundException("Class '$name' not found");
       }
       return new $name(... array_values($constructor));
   }

需要在new的時(shí)候，同時(shí)加入到instances屬性中，修改后如下：
```php
public function make(string $name, array $constructor = [])
    {
        if (!class_exists($name)) {
            throw new NotFoundException("Class '$name' not found");
        }
        // return new $name(... array_values($constructor));
        $this->instances[$name] = new $name(... array_values($constructor));
        return $this->instances[$name];
    }

2. 發(fā)現(xiàn)make()方法執(zhí)行是在中間件的Container::get()之后，分析src/App.php的流程，可以對(duì)getCallback()方法進(jìn)行修改，多傳遞一個(gè)request參數(shù)，然后稍微調(diào)整，就可以讓make()方法先執(zhí)行，修改后代碼如下：

   protected static function getCallback(string $plugin, string $app, $call, array $args = null, bool $withGlobalMiddleware = true, RouteObject $route = null)
   {
       $args = $args === null ? null : array_values($args);
       $middlewares = [];
       if ($route) {
           $routeMiddlewares = array_reverse($route->getMiddleware());
           foreach ($routeMiddlewares as $className) {
               $middlewares[] = [$className, 'process'];
           }
       }
       $middlewares = array_merge($middlewares, Middleware::getMiddleware($plugin, $app, $withGlobalMiddleware));
   
       foreach ($middlewares as $key => $item) {
           $middleware = $item[0];
           if (is_string($middleware)) {
               $middleware = static::container($plugin)->get($middleware);
           } elseif ($middleware instanceof Closure) {
               $middleware = call_user_func($middleware, static::container($plugin));
           }
           if (!$middleware instanceof MiddlewareInterface) {
               throw new InvalidArgumentException('Not support middleware type');
           }
           $middlewares[$key][0] = $middleware;
       }
   
       $needInject = static::isNeedInject($call, $args);
       if (is_array($call) && is_string($call[0])) {
           $controllerReuse = static::config($plugin, 'app.controller_reuse', true);
           if (!$controllerReuse) {
               if ($needInject) {
                   $call = function ($request, ...$args) use ($call, $plugin) {
                       $call[0] = static::container($plugin)->make($call[0], [$request]);
                       $reflector = static::getReflector($call);
                       $args = static::resolveMethodDependencies($plugin, $request, $args, $reflector);
                       return $call(...$args);
                   };
                   $needInject = false;
               } else {
                   $call = function ($request, ...$args) use ($call, $plugin) {
                       $call[0] = static::container($plugin)->make($call[0], [$request]);
                       return $call($request, ...$args);
                   };
               }
           } else {
               $call[0] = static::container($plugin)->get($call[0]);
           }
       }
   
       if ($needInject) {
           $call = static::resolveInject($plugin, $call);
       }
   
       if ($middlewares) {
           $callback = array_reduce($middlewares, function ($carry, $pipe) {
               return function ($request) use ($carry, $pipe) {
                   try {
                       return $pipe($request, $carry);
                   } catch (Throwable $e) {
                       return static::exceptionResponse($e, $request);
                   }
               };
           }, function ($request) use ($call, $args) {
               try {
                   if ($args === null) {
                       $response = $call($request);
                   } else {
                       $response = $call($request, ...$args);
                   }
               } catch (Throwable $e) {
                   return static::exceptionResponse($e, $request);
               }
               if (!$response instanceof Response) {
                   if (!is_string($response)) {
                       $response = static::stringify($response);
                   }
                   $response = new Response(200, [], $response);
               }
               return $response;
           });
       } else {
           if ($args === null) {
               $callback = $call;
           } else {
               $callback = function ($request) use ($call, $args) {
                   return $call($request, ...$args);
               };
           }
       }
       return $callback;
   }

   改動(dòng)對(duì)比圖：
   

3. 對(duì)調(diào)用getCallback()的兩個(gè)地方，加上request參數(shù)
   165 行

   $callback = static::getCallback($plugin, $app, [$controller, $action]);

   改為：

   $callback = static::getCallback($plugin, $app, [$controller, $action], $args = null, $withGlobalMiddleware = true, $route = null, $request);

大概557行

$callback = static::getCallback($plugin, $app, $callback, $args, true, $route);

改為

$callback = static::getCallback($plugin, $app, $callback, $args, true, $route, $request);

好了，重新調(diào)試，OK!