Call to undefined method Illuminate\Support\Facades\Request::all()

版本：laravel5.8       

system: win10+php7.2+nginx1.5+mysql5.7

以下写法报错（Call to undefined method Illuminate\Support\Facades\Request::all()）：

```

use Illuminate\Support\Facades\Request;

public function upload(Request $request) {

        dd($request->all());

 }

但是以下写法就可以：

use Illuminate\Support\Facades\Request;

public function upload(Request $request) {

        dd(Request::all());

 }

请问这是为什么？

```