hasFile 函数在 Laravel5.8 中不起作用

对于具有此名称的选择文件，我有 3 个输入：

docs['selfie']
docs['id_card']
docs['bank_card']

我想检查是否docs['selfie']有文件返回yes否则返回no。但总是回来no

功能：

    public function Document(Request $request)
    {
        if ($request->hasFile("docs['selfie']")) {
            return "yes";
        }
        else {
            return "no";
        }
    }

并形成：

{{ html()->form('POST', route('frontend.user.send.document'))->class('form-horizontal')->Attribute('enctype','multipart/form-data')->open() }}
<div class="row">
    <div class="col-md-12">
        <div class="form-group row">
            <label class="col-form-label col-lg-2">id card</label>
            <div class="col-lg-10">
                <div class="custom-file">
                    <input type="file" class="custom-file-input" id="National_Card" name="docs['id_Card']">
                    <label class="custom-file-label" for="docs">chose file</label>
                </div>
            </div>
        </div>
    </div>
    <div class="col-md-12">
        <div class="form-group row">
            <label class="col-form-label col-lg-2">bank card</label>
            <div class="col-lg-10">
                <div class="custom-file">
                    <input type="file" class="custom-file-input" id="Bank_card" name="docs['bank_card']">
                    <label class="custom-file-label" for="Bank_card">chose file</label>
                </div>
            </div>
        </div>
    </div>
    <div class="col-md-12">
            <div class="form-group row">
                <label class="col-form-label col-lg-2">selfie</label>
                <div class="col-lg-8">
                    <div class="custom-file">
                        <input type="file" class="custom-file-input" id="Selfie" name="docs['selfie']">
                        <label class="custom-file-label" for="Selfie">chose file</label>
                    </div>
                </div>
                <div class="col-lg-2">
                    <button type="button" class="btn btn-primary"  data-toggle="modal" data-target="#selfie_modal">see example</button>
                </div>                
            </div>
        </div>
    </div>
    <div class="row">
        <div class="col">
            <div class="form-group mb-0 clearfix">
                {{ form_submit("send docs" . ' ') }}
            </div><!--form-group-->
        </div><!--col-->
    </div><!--row-->
{{ html()->form()->close() }}