请大家先看一下下面的问题，帮忙解决一下，谢谢啦！
本地搭建的php+nginx环境，thinkphp3.1的框架。
Call to a member function get() on null D:\phpStudy\WWW\qj\ThinkPHP\Extend\Driver\TagLib\TagLibGyfx.class.php 第 589 行.
错误位置
FILE: D:\phpStudy\WWW\qj\ThinkPHP\Lib\Core\Think.class.php LINE: 277
TRACE
[17-02-25 08:51:02] D:\phpStudy\WWW\qj\ThinkPHP\Lib\Core\Think.class.php (277) halt(Call to a member function get() on null D:\phpStudy\WWW\qj\ThinkPHP\Extend\Driver\TagLib\TagLibGyfx.class.php 第 589 行.)
[17-02-25 08:51:02] D:\phpStudy\WWW\qj\ThinkPHP\Lib\Core\Think.class.php (292) Think::appError(1, Call to a member function get() on null, D:\phpStudy\WWW\qj\ThinkPHP\Extend\Driver\TagLib\TagLibGyfx.class.php, 589)
[17-02-25 08:51:02] () Think::fatalError()
ThinkPHP3.1.2 { Fast & Simple OOP PHP Framework } -- [ WE CAN DO IT JUST THINK ]
本地自定义标签文件目录：
D:\phpStudy\WWW\qj\ThinkPHP\Extend\Driver\TagLib\TagLibGyfx.class.php
问题所在代码：
/**
* 自定义主导航标签
* <gyfx:navigation name='navigation' row='8' position="middle"></gyfx:navigation>
* @param type $attr
* @param type $content
*/
public function _navigation($attr, $content){
$parseStr = '';
$tag = $this->parseXmlAttr($attr, 'navigation');
//dump($tag);die();
$name = $tag['name'];
$row = !empty($tag['row']) ? $tag['row'] : '12';
$position = !empty($tag['position']) ? $tag['position'] : 'top';
//实例化缓存
if(C('DATA_CACHE_TYPE') == 'MEMCACHED' && C('MEMCACHED_OCS') == true){
$memcaches = new Cacheds();
}else{
$memcaches = new Caches();
}
//生成一个用来保存 namespace 的 key
if($memcaches->getStat()){
$ns_key = $memcaches->C()->get(CI_SN."_namespace_key");
//如果 key 不存在，则创建，默认使用当前的时间戳作为标识
if($ns_key===false) $memcaches->C()->set(CI_SN."_namespace_key",time());
}
//根据tag获取缓存key
$cache_key = json_encode($tag).CI_SN;
$cache_key = $ns_key.$cache_key;
if($memcaches->getStat() && ini_get('memcache.allow_failover')&& $ary_return = $memcaches->C()->get($cache_key)){
$list = json_decode($ary_return,true);
}else{
$list = D("Nav")->where(array('n_status'=>'1','n_position'=>$position))
->field('n_id as nid,n_name as nname,n_url as nurl,n_target as ntarget, n_order as norder ')
->order(array('n_order' => 'asc'))->limit($row)->select();
//处理数据
if(!empty($list) && is_array($list)){
foreach($list as &$slist){
if(strstr($slist['nurl'],"?")){
$slist['nurl'] =
$slist['nurl'].'&name='.$slist['nname'];
}else{
$slist['nurl'] = $slist['nurl'];
}
}
}
if($memcaches->getStat() && ini_get('memcache.allow_failover')){
$memcaches->C()->set($cache_key,json_encode($list));
}
}
$count = count($list);
$str_list = var_export($list, true);
$parseStr = $parseStr . "<?php $$name = " . $str_list . "; ?>";
$parseStr = $parseStr . "<?php \$nav_count = " . $count . "; ?>";
$parseStr = $parseStr . '<volist name="nav" id="' . $name . '" >' . $content . '</volist>';
return $parseStr;
}
**第589行：$ns_key = $memcaches->C()->get(CI_SN."_namespace_key");
我打印到那一步都是好的，再往下就出现题目的错误了。587行，我刚更新的截图
