在微信测试号上检测如图所示 ，各位看看是什么问题  代码检查不出来啊

public function definedItem(){
        header('content-type:text/html;charset=utf8');
        echo $access_token=$this->getWxAccessToken();
        echo '<br />';
        
            $url=" https://api.weixin.qq.com/cgi-bin/menu/create?access_token=".$access_token;
            
            echo '<br />';
            $postArr= array(
                    'button'=>array(
                        array(
                            'name'=>urlencode('XXX'),
                            'type'=>'click',
                            'key'=>'item1',
                            ),
                        array(
                            'name'=>urlencode('XXX'),
                            'sub_button'=>array(
                        array(
                            'name'=>urlencode('XXX'),
                            'type'=>'click',
                            'key'=>'balabala',
                            ),
                        array(
                            'name'=>urlencode('XXX'),
                            'type'=>'click',
                            'key'=>'lal ',
                                ),
                            ),
                        ),
                        array(
                            'name'=>urlencode('XXX'),
                            'type'=>'view',
                            'url'=>'http://XXXX/stu'
                            )
                ),    
            );

        echo $postJson = urldecode(json_encode($postArr));
        $res=$this->http_curl($url,'post','json',$postJson);
        var_dump($res);
    }

···XXX是我替换了的

{"buttun":[
{"name":"XXX","type":"click","key":"item1"}
,{"name":"XXX","sub_button":[{"name":"XXX","type":"click","key":"balabala"},
{"name":"XXX","type":"click","key":"lal "}]},
{"name":"XXX","type":"view","url":"http:\/\/XXX\/stu"}]}NULL

哪路大神来看看