public function index(Request $request)
 {
     // 获取排序条件
     $orderColumn = $request->get('sort_up', $request->get('sort_down', 'created_at'));
     $direction = $request->get('sort_up') ? 'asc' : 'desc';
     $classrooms = Classroom::orderBy($orderColumn, $direction)->paginate(8);
     $stores = json_encode(DB::table('stores')->where('deleted_at', null)->select('id', 'name')->get());
     return view('admin.classroom.list', compact('classrooms', 'stores', 'query'));
 }
 /**
  * Display a listing of the resource.
  *
  * @return Response
  */
 public function index()
 {
     $classrooms = Classroom::orderBy('id', 'desc')->paginate(10);
     return view('classrooms.index', compact('classrooms'));
 }