C#递归加载目录树

         /// 获取目录管理信息集合
         /// </summary>
         /// <returns></returns>
         public List<CatalogTree> GetCatalogTree()
         {
             List<CatalogTree> list = new List<CatalogTree>();
             var db = DatabaseFactory.CreateDatabase("ELManage");
             string sql = "select KeyId,CatalogName,ParentId,SortCode,IsFolder  from EL_Catalog  where EnableMark=1";
             DbCommand cmd = db.GetSqlStringCommand(sql);
             DataTable dt = db.ExecuteDataTable(cmd);
             ; i < dt.Rows.Count; i++)
             {
                 DataRow dr = dt.Rows[i];
                 CatalogTree model = new CatalogTree();
                 model.keyid = Convert.ToString(dr["KeyId"]);
                 model.catalogname = Convert.ToString(dr["CatalogName"]);
                 model.parentid = Convert.ToString(dr["ParentId"]);
                 if (!Convert.IsDBNull(dr["SortCode"]))
                 {
                     model.sortcode = Convert.ToInt32(dr["SortCode"]);
                 }
                 if (!Convert.IsDBNull(dr["IsFolder"]))
                 {
                     model.isfolder = Convert.ToInt32(dr["IsFolder"]);
                 }
                 list.Add(model);
             }
         //获取根节点
             var mds = list.Where(c => c.parentid == "-").OrderBy(t => t.sortcode).ToList();
             foreach (var item in mds)
             {
           //获取子节点
                 item.children = GetChildrens(list, item);
             }
             return mds;
         }

递归获取子节点：

         /// 获取目录管理信息集合
         /// </summary>
         /// <returns></returns>
         public List<CatalogTree> GetCatalogTree()
         {
             List<CatalogTree> list = new List<CatalogTree>();
             var db = DatabaseFactory.CreateDatabase("ELManage");
             string sql = "select KeyId,CatalogName,ParentId,SortCode,IsFolder,TableName from EL_Catalog  where EnableMark=1";
             DbCommand cmd = db.GetSqlStringCommand(sql);
             DataTable dt = db.ExecuteDataTable(cmd);
             ; i < dt.Rows.Count; i++)
             {
                 DataRow dr = dt.Rows[i];
                 CatalogTree model = new CatalogTree();
                 model.keyid = Convert.ToString(dr["KeyId"]);
                 model.catalogname = Convert.ToString(dr["CatalogName"]);
                 model.parentid = Convert.ToString(dr["ParentId"]);
                 if (!Convert.IsDBNull(dr["SortCode"]))
                 {
                     model.sortcode = Convert.ToInt32(dr["SortCode"]);
                 }
                 if (!Convert.IsDBNull(dr["IsFolder"]))
                 {
                     model.isfolder = Convert.ToInt32(dr["IsFolder"]);
                 }
                 list.Add(model);
             }
         //获取根节点
             var mds = list.Where(c => c.parentid == "-").OrderBy(t => t.sortcode).ToList();
             foreach (var item in mds)
             {
           //获取子节点
                 item.children = GetChildrens(list, item);
             }
             return mds;
         }