PHP编程：基于递归实现的php树形菜单代码

public function procCategory($sid,$pid){
$return = array();
$key = 0;
static $arr = array(); //分类级别参考数组
$sql =? "select cid,pcid,name from shop_goods_catalog where sid='{$sid}' and pcid = '{$pid}'";
$result = $this->__db->query($sql);
?
while($row=$this->__db->fetchArray($result)){
$nbsp = '';
if($row['pcid']==0){
$arr = array();
}
$arr[] = $row['pcid'];
//顶级分类不添加树形结构标识.
if($row['pcid']>0){
//根据分类级别添加树形结构标识
$key = array_search($row['pcid'],$arr);
for($i=0;$i<$key;$i++){
$nbsp .= '??';
}
//重构分类级别参考数组
if(count($arr)>1&&count(array_keys($arr,$row['pcid']))>1){
$arr = array_slice($arr,$key+1);
}
}
$row['name'] = $nbsp.$row['name'];
$row['level'] = $key; //分类级别,0为顶级分类,1为二级分类,用于样式设定或其他需求
$return[] = $row;
$r = $this->procCategory($sid,$row['cid']);
$return = array_merge($return,$r);
}
?
return $return;
}