TP框架封装无限极分类

<?phpnamespace Admin\Model;use Think\Model;class CatModel extends Model{protected $cats = array();public function __construct(){parent::__construct();$this->cats = $this->select();}public function getTree($parent_id = 0,$lev = 0){$tree = array();//声明一个数组 方便把循环出来的值保存起来foreach($this->cats as $c){if($c['parent_id'] == $parent_id){//把parent_id为0的栏目先取出$tree[] = $c;//每循环一次就把父parent_id和子parent_id对应值的保存起来$tree = array_merge($tree,$this->getTree($c['cat_id'],$lev+1));//把$c下的cat_id放在函数再循环一次 为了$tree在循环里不会后者覆盖前者   用array_merge函数拼接数组}}return $tree;}}