//实现无限级分类

 public functiongetTree(){ $categorys = Category::all();
        return $this->makeTree($categorys, 'cate_id', 'cate_pid', 'cate_name', 0);
    }

public  functionmakeTree($list,$pk='id',$pid='pid',$child='child',$root=0){
$tree = array();
foreach ($list as $key => $val) {
    if ($val[$pid] == $root) {
        //获取当前$pid所有子类                unset($list[$key]);
        if (!empty($list)) {
            $tmpChild = self::makeTree($list, $pk, $pid, $child, $val[$pk]);
            if (!empty($tmpChild)) {
                $val['_' . $child] = $tmpChild;
            }
        }
        $tree[] = $val;
    }
}
return $tree;
}