asp.net mvc+EF 递归生成树结构返回json

0、数据表结构，主要属性有：Id、parentId（父节Id）、Text、Url……等等。

1、新建一个树结构MenuModels

   public class MenuModels
    {
        private int _id;
        private string _text;
        private int? _parentid;
        private string _icon;
        private string _url;
        private object _menus;
        private Dictionary<string, string> _attributes = new Dictionary<string, string>();

        public int id
        {
            get { return _id; }
            set { _id = value; }
        }
        public int? parentid
        {
            get { return _parentid; }
            set { _parentid = value; }
        }
        public string text
        {
            get { return _text; }
            set { _text = value; }
        }
        public string icon
        {
            get { return _icon; }
            set { _icon = value; }
        }
        public string url
        {
            get { return _url; }
            set { _url = value; }
        }
        public Dictionary<string, string> attributes
        {
            get { return _attributes; }
            set { _attributes = value; }
        }
        public object menus
        {
            get { return _menus; }
            set { _menus = value; }
        }
    }

2、在控制器中新建如下方法：

/// <summary>
        /// 加载树
        /// </summary>
        /// <returns></returns>
        public JsonResult LoadTree()
        {
            List<MenuModels> list = InitTree();
            return Json(list, "text/html", JsonRequestBehavior.AllowGet);
        }

 /// <summary>
        /// 初始化树 默认找出顶级菜单
        /// </summary>
        /// <returns></returns>
        public List<MenuModels> InitTree()
        {
            var TreeList = _db.Cent_Tree.ToList();
            List<MenuModels> rootNode = new List<MenuModels>();
            foreach (var plist in TreeList.Where(t => t.ParentID == null))
            {
                MenuModels jt = new MenuModels();
                jt.id = plist.ID;
                jt.text = plist.Name;
                jt.parentid = plist.ParentID;
                jt.icon = "";
                jt.url = plist.SystemUrl;
                jt.attributes = CreateUrl(TreeList, jt);
                jt.menus = CreateChildTree(TreeList, jt);
                rootNode.Add(jt);
            }
            return rootNode;
        }
        /// <summary>
        /// 递归生成子树
        /// </summary>
        /// <param name="TreeList"></param>
        /// <param name="jt"></param>
        /// <returns></returns>
        private List<MenuModels> CreateChildTree(List<Cent_Tree> TreeList, MenuModels jt)
        {
            int keyid = jt.id;//根节点ID
            List<MenuModels> nodeList = new List<MenuModels>();
            var children = TreeList.Where(t => t.ParentID == keyid);
            foreach (var chl in children)
            {
                MenuModels node = new MenuModels();
                node.id = chl.ID;
                node.text = chl.Name;
                node.parentid = chl.ParentID;
                node.icon = "";
                node.url = chl.SystemUrl;
                node.attributes = CreateUrl(TreeList, node);
                node.menus = CreateChildTree(TreeList, node);
                nodeList.Add(node);
            }
            return nodeList;
        }
        /// <summary>
        /// 把Url属性添加到attribute中，如果需要别的属性，也可以在这里添加
        /// </summary>
        /// <param name="TreeList"></param>
        /// <param name="jt"></param>
        /// <returns></returns>
        private Dictionary<string, string> CreateUrl(List<Cent_Tree> TreeList, MenuModels jt)
        {
            Dictionary<string, string> dic = new Dictionary<string, string>();
            int keyid = jt.id;
            var urlList = TreeList.Where(t => t.ID == keyid).SingleOrDefault();
            string Sysurl = urlList.SystemUrl;
            string Indexurl = urlList.IndexUrl;
            dic.Add("sysurl", Sysurl);
            dic.Add("indurl", Indexurl);
            dic.Add("close", "true");
            return dic;
        }

3、运行，http://localhost/Home/loadtree