PFinal\Wechat\Api::buildReply PHP Method

    public function buildReply($reply)
    {
        //回复的消息为null，会返回给微信一个"success"，微信服务器不会对此作任何处理，并且不会发起重试
        if (is_null($reply)) {
            return 'success';
        }
        if (is_string($reply) || is_numeric($reply)) {
            $reply = new Text("{$reply}");
        }
        //索引数组，多图文消息
        if (is_array($reply) && array_keys($reply) === range(0, count($reply) - 1)) {
            if ($reply[0] instanceof News) {
                $reply = new News($reply);
            }
        }
        if (!$reply instanceof ReplyMessage) {
            throw new WechatException('Argument $reply must implement interface PFinal\\Wechat\\Contract\\ReplyMessage');
        }
        //手动构建好的xml字符串
        if (strtolower($reply->type()) === 'raw') {
            return $this->attemptEncrypt($reply->xmlData());
        }
        $data = array('ToUserName' => $this->getMessage()->FromUserName, 'FromUserName' => $this->getMessage()->ToUserName, 'CreateTime' => time(), 'MsgType' => $reply->type());
        $data = array_merge($data, $reply->xmlData());
        $data = Xml::build($data);
        return $this->attemptEncrypt($data);
    }