Laravel 5 将临时附件发送到不适用于Laravel 5.8的电子邮件

我正试图通过通知电子邮件从表单输入发送附件，但我一直收到“不允许对'illumb\Http\UploadedFile'进行序列化”错误

这是我的控制器功能：

/**
 * @param InterviewRequest $request
 * @return $this|\Illuminate\Http\RedirectResponse|\Illuminate\Routing\Redirector
 */
public function interviewPost(InterviewRequest $request)
{
    $contactForm = $request->all();
    $contactForm['country_code'] = config('country.code');
    $contactForm['country_name'] = config('country.name');
    $contactForm = ArrayHelper::toObject($contactForm);

    if ($request->hasFile('filename')) {
        $contactForm->filename = $request->file('filename');
    }

    // Send Contact Email
        if (config('settings.app.email')) {
            Notification::route('mail', config('settings.app.email'))->notify(new InterviewSent($contactForm)); 
   }
}

/**
 * @param  mixed  $notifiable
 * @return \Illuminate\Notifications\Messages\MailMessage
 */
public function toMail($notifiable)
{
    $mailMessage = (new MailMessage)
        ->replyTo($this->msg->email, $this->msg->name)
        ->subject(trans('mail.contact_form_title', ['country' => $this->msg->country_name, 'appName' => config('app.name')]))
        ->line(t('Country') . ': <a href="' . lurl('/?d=' . $this->msg->country_code) . '">' . $this->msg->country_name . '</a>')
        ->line(t('Name') . ': ' . $this->msg->name);

    if (isset($this->msg->email) && $this->msg->email!='') {
        $mailMessage->line(t('Email Address') . ': ' . $this->msg->email);
    }

    if (isset($this->msg->phone) && $this->msg->phone!='') {
        $mailMessage->line(t('Phone Number') . ': ' . $this->msg->phone);
    }

    if (isset($this->msg->filename)  && (!empty($filename))) {
        return $mailMessage->attachData(
            $this->msg->filename->path(),
            $this->msg->filename->getClientOriginalName(),
            [
            'mime' => $this->msg->filename->getMimeType(),
        ]);
    }

    return $mailMessage;
}

这是我的通知功能：

/**
 * @param InterviewRequest $request
 * @return $this|\Illuminate\Http\RedirectResponse|\Illuminate\Routing\Redirector
 */
public function interviewPost(InterviewRequest $request)
{
    $contactForm = $request->all();
    $contactForm['country_code'] = config('country.code');
    $contactForm['country_name'] = config('country.name');
    $contactForm = ArrayHelper::toObject($contactForm);

    if ($request->hasFile('filename')) {
        $contactForm->filename = $request->file('filename');
    }

    // Send Contact Email
        if (config('settings.app.email')) {
            Notification::route('mail', config('settings.app.email'))->notify(new InterviewSent($contactForm)); 
   }
}

/**
 * @param  mixed  $notifiable
 * @return \Illuminate\Notifications\Messages\MailMessage
 */
public function toMail($notifiable)
{
    $mailMessage = (new MailMessage)
        ->replyTo($this->msg->email, $this->msg->name)
        ->subject(trans('mail.contact_form_title', ['country' => $this->msg->country_name, 'appName' => config('app.name')]))
        ->line(t('Country') . ': <a href="' . lurl('/?d=' . $this->msg->country_code) . '">' . $this->msg->country_name . '</a>')
        ->line(t('Name') . ': ' . $this->msg->name);

    if (isset($this->msg->email) && $this->msg->email!='') {
        $mailMessage->line(t('Email Address') . ': ' . $this->msg->email);
    }

    if (isset($this->msg->phone) && $this->msg->phone!='') {
        $mailMessage->line(t('Phone Number') . ': ' . $this->msg->phone);
    }

    if (isset($this->msg->filename)  && (!empty($filename))) {
        return $mailMessage->attachData(
            $this->msg->filename->path(),
            $this->msg->filename->getClientOriginalName(),
            [
            'mime' => $this->msg->filename->getMimeType(),
        ]);
    }

    return $mailMessage;
}

/**
*@param混合$应呈报
*@return\light\Notifications\Messages\MailMessage
*/
托梅尔的公共职能（应呈报）
{
$mailMessage=（新的mailMessage）
->回复（$this->msg->email，$this->msg->name）
->主题（trans（'mail.contact_form_title'，['country'=>this->msg->country_name，'appName'=>config（'app.name'）））
->行（t（'国家'）：'）
->行（t（'Name'）：'。$this->msg->Name）；
如果（设置（$this->msg->email）&&&$this->msg->email！=''）{
$mailMessage->line（t（'Email Address'）：'。$this->msg->Email）；
}
如果（设置（$this->msg->phone）&&&$this->msg->phone！=''）{
$mailMessage->line（t（'Phone Number'）：'。$this->msg->Phone）；
}
如果（设置（$this->msg->filename）&&（！empty（$filename）））{
返回$mailMessage->attachData(
$this->msg->filename->path（），
$this->msg->filename->getClientOriginalName（），
[
'mime'=>this->msg->filename->getMimeType（），
]);
}
返回$mailMessage；
}

我还尝试使用attach（）方法，但结果仍然相同