用微信自带的消息接口调试都成功获得回应，但关注了公众号却没有回复。而且我发现在php里加入了一句插入数据库的代码，发现根本没运行（接口调试时有运行）。究竟什么原因？

<?php
namespace Home\Controller;
use Think\Controller;
class WeixinController extends BaseController {

    public function index(){
        //define your token
        define("TOKEN", C("TOKEN"));
        $wechatObj = new \Weixin\weixin();

        if (isset($_GET['echostr'])) {
            $wechatObj->valid();
        }else{
            $this->responseMsg();
        }

    }

    private function responseMsg(){
        //get post data, May be due to the different environments
        $postStr = $GLOBALS["HTTP_RAW_POST_DATA"];

        //extract post data
        if (!empty($postStr)){
                /* libxml_disable_entity_loader is to prevent XML eXternal Entity Injection,
                   the best way is to check the validity of xml by yourself */
                libxml_disable_entity_loader(true);
                $postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);
                $fromUsername = $postObj->FromUserName;
                $toUsername = $postObj->ToUserName;
                $keyword = trim($postObj->Content);
                $time = time();
                $textTpl = "<xml>
                            <ToUserName><![CDATA[%s]]></ToUserName>
                            <FromUserName><![CDATA[%s]]></FromUserName>
                            <CreateTime>%s</CreateTime>
                            <MsgType><![CDATA[%s]]></MsgType>
                            <Content><![CDATA[%s]]></Content>
                            <FuncFlag>0</FuncFlag>
                            </xml>";             
                if(!empty( $keyword ))
                {
                    $msgType = "text";
                    $contentStr = "Welcome to wechat world!";
                    $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $keyword);
                    echo $resultStr;
                }else{
                    echo "Input something...";
                }

        }else {
            echo "";
            exit;
        }
    }
    private function test($content){
        $m = M('list');
        return $m->execute("UPDATE list SET website = '{$content}' WHERE name = 'test'");
    }


}