Laravel 8 使用mailable发送邮件，undefined variable错误

Laravel 8 使用mailable的方法发送邮件，一直出现undefined variable的错误，但是参照网上的解决方案，使用public定义variable，但是还是报同样的错误

    public $jobdocumentmessage;

    /**
     * Create a new message instance.
     *
     * @return void
     */
    public function __construct($jobdocumentmessage)
    {
        $this->jobdocumentmessage = $jobdocumentmessage;
    }

    /**
     * Build the message.
     *
     * @return $this
     */
    public function build()
    {
        #dd($jobdocumentmessage);
        return $this->view('emails.jobDocument')
                    ->with([
                        'body' => $jobdocumentmessage->body,
                        'user' => $jobdocumentmessage->user,
                        ])
                    ->subject($jobdocumentmessage->subject)
                    ->replyTo($jobdocumentmessage->mail)
                    ->attach($jobdocumentmessage->url, ['as' => $jobdocumentmessage->name
                ]);
    }