为什么我持续获得PATCH ... 500（内部服务器错误），即使我有csrf令牌？ 在我的laravel和vue js应用程序中

Question

This my where I submit my form to vue resource

<meta id="token" name="token" value="{{ csrf_token() }}">

<div class="modal fade" id="editroom" tabindex="-1" role="dialog" aria-labelledby="myModalLabel">
      <div class="modal-dialog" role="document">
        <div class="modal-content">
          <div class="modal-header">
            <button type="button" class="close" data-dismiss="modal" aria-label="Close">
              <span aria-hidden="true">×</span>
            </button>
            <h4 class="modal-title" id="myModalLabel">Edit Blog Post</h4>
          </div>
          <div class="modal-body">
            <form method="post" enctype="multipart/form-data" v-on:submit.prevent="updateRoom(fillRoom.id)">
            {{ csrf_field() }}
              <div class="form-group">
                <label for="title">Room Number:</label>
                <input type="text" name="title" class="form-control" v-model="fillRoom.rn" />
              </div>
                <div class="form-group">
                  <label for="title">Status:</label>
                  <input type="text" name="title" class="form-control" v-model="fillRoom.status" />
                </div>
              <div class="form-group">
                <button type="submit" class="btn btn-success">Submit</button>
              </div>
            </form>
          </div>
        </div>
      </div>
    </div>

This is my vue-resource/ajax. that calls the routes

 Vue.http.headers.common['X-CSRF-TOKEN'] = $("#token").attr("value");
new Vue({

    el: "#app",
    data:{
        newRoom: {'rt': ''},
        rooms: [],
        dT: '',
        fillRoom : {'rn':'','status':'', 'id': ''}
    },

mounted: function() {
    this.getRooms();
  },

    methods:{


        editRoom: function(room){
          this.fillRoom.rn = room.room_no;
          this.fillRoom.status = room.status;
          this.fillRoom.id = room.room_id;
          $("#editroom").modal('show');
        },


         updateRoom: function(id) {
          var input = this.fillRoom;
          this.$http.patch('/admin_page/rooms/'+id,input).then(response => {
            this.newRoom = {'rt': ''};
            $("#edit-item").modal('hide');
            toastr.success('Item Updated Successfully.', 'Success Alert', {timeOut: 5000});
          }, response => {
            console.log(response.date);
          });
        },



    }

});

And this my route resource that calls the controller

Route::group(['middleware' => ['web']], function() {
  Route::get('/admin_page/rooms_page', 'RoomController@rooms_page');
  Route::resource('admin_page/rooms', 'RoomController');
});

finally, this is my controller. it return json data after update

public function update(Request $request, $id)
    {
        $query = DB::table('rooms')
            ->where('id', $id)
            ->update(['room_no' => $request->input('rn')]);

            return response()->json($query);
    }