关于c#:树形结构数据获取

记录代码如下：
/// <summary>

    /// 返回树形下拉框 菜单数据    /// </summary>    /// <returns></returns>    [HttpGet]    public ActionResult GetTreeList(int hosid=0,int pid=0)    {        var hoslist = yqBll.GetListall();        var dptmodel = departmentBLL.GetModelList(" F_State=1");        dptmodel.Sort((x, y) => x.F_Sort ?? 0 - y.F_Sort ?? 0);//排序        var treeList = new List<TreeModel>();        if (hoslist.Count > 0)        {            foreach (var hositem in hoslist)            {                TreeModel treeModel = new TreeModel();                treeModel.id = hositem.T_Woid.ToString();                treeModel.IconCls = "";                treeModel.text = hositem.T_Woname;                treeModel.parentid = "-1";                treeModel.TypeId = 1;                treeModel.children = TreeRecursion(dptmodel, "0", hositem.T_Woid);                treeList.Add(treeModel);                //var dptlist = dptmodel.Where(p => p.F_ParentId == 0 && p.T_Woid == hositem.T_Woid).ToList();            }        }        //return Content(treeList.ToJson());        return Success("获取菜单树胜利", treeList);    }    private List<TreeModel> TreeRecursion(List<Model.T_Sys_Department> data, string parentId = "0", int hosid = 0)    {        List<Model.T_Sys_Department> item = null;        List<TreeModel> newList = new List<TreeModel>();        //if (parentId != "0")        //{        if (hosid != 0)        {            item = data.FindAll(t => t.F_ParentId.ToString() == parentId && t.T_Woid == hosid);//data倡议在调用此扩大办法前曾经排序过        }        else        {            item = data.FindAll(t => t.F_ParentId.ToString() == parentId);//data倡议在调用此扩大办法前曾经排序过        }        if (item.Count > 0)        {            foreach (Model.T_Sys_Department entity in item)            {                TreeModel treeModel = new TreeModel();                treeModel.id = entity.F_DeptId.ToString();                treeModel.IconCls = "";                treeModel.text = entity.F_DeptName;                treeModel.parentid = entity.F_ParentId.ToString();                treeModel.TypeId = 2;                treeModel.children = TreeRecursion(item, entity.F_DeptId.ToString());                newList.Add(treeModel);            }        }        //}        return newList;    }