1. <?php
    2. 我们想要在部分路由上完全禁用浏览器缓存，比如验证码，或者其它要求不能在浏览器端缓存的页面，我们可以建立如下一个中间件来完成：
    3. app/Http/Middleware/NoHttpCache.php:
    4. <?php 
    5. namespace App\Http\Middleware;
    6. use Closure;use Illuminate\Contracts\Routing\Middleware;
    7. use Illuminate\Http\Response;
    8. use Symfony\Component\HttpFoundation\Response as SymfonyResponse;
    10. class NoHttpCache implements Middleware {
    11.     /**
    12.      * Handle an incoming request.
    13.      *
    14.      * @param  \Illuminate\Http\Request  $request
    15.      * @param  \Closure  $next
    16.      * @return mixed
    17.      */
    18.     public function handle($request, Closure $next)
    19.     {
    20.         $response = $next($request);
    22.         // This step is only needed if you are returning        // a view in your Controller or elsewhere, because        // when returning a view `$next($request)` returns        // a View object, not a Response object, so we need        // to wrap the View back in a Response.        if ( ! $response instanceof SymfonyResponse) {
    23.             $response = new Response($response);
    24.         }
    26.         /**
    27.          * @var  $headers  \Symfony\Component\HttpFoundation\HeaderBag
    28.          */
    29.         $response->header('Pragma', 'no-cache');
    30.         $response->header('Expires', 'Fri, 01 Jan 1990 00:00:00 GMT');
    31.         $response->header('Cache-Control', 'no-cache, must-revalidate, no-store, max-age=0, private');
    33.         return $response;
    34.     }}
    35. 然后在 app/Http/Kernel.php 中 $routeMiddleware 中注册它就可以在路由中使用了：
    36. ...use App\Http\Middleware\NoHttpCache;.../**
    37.  * The application's route middleware.
    38.  *
    39.  * @var array
    40.  */protected $routeMiddleware = [
    41.     'no_http_cache' => NoHttpCache::class,];
    42. 在 routes.php 中对要禁用缓存的路由添加中间件：
    43. Route::get('foo/bar', ['middleware' => 'no_http_cache', function () {
    44.     // ...}]);