【已解决】$request->file()返回空对象

<form action="http://127.0.0.1:8787/v1/upload/file" method="post" enctype="multipart/form-data">
    <input type="file" name="file">
    <button type="submit">GO</button>
</form>

public function upload(Request $request)
    {
        return $this->success($request->file());
    }