yii2实现三级菜单及以上(只提供核心代码)

sql:

sql内容：

model：AddonGolfArticleCate.php

public  function listToTree($lists, $childKey = 'children'){
        $map = [];
        $res = [];
        foreach($lists as $id => &$item){
            $pid = &$item['pid'];
            $map[$item['id']] = &$item;
            if(!isset($map[$pid])){
                $res[$id] = &$item;
            }else{
                $pItem = &$map[$pid];
                $pItem[$childKey][] = &$item;
            }
        }
        return $res;
    }

控制器：

$articleCate=AddonGolfArticleCate::find()->select('*')->asArray()->all();
            $cates=new AddonGolfArticleCate();
            $tree=$cates->listToTree($articleCate);
            $trees=array_column($tree,null);
            return $this->render("introduction",[
                  'trees'=>$trees,
                  'articleCates'=>$articleCates
            ]);

视图：

一级菜单：

$val['title']

二级菜单：

$vall['title]

三级菜单：

$valll['title']