递归获取子结点(包括自身结点)

         #region 递归获取子结点(包括自身结点)
        /// <summary>
        /// 递归获取子结点(包括自身结点)
        /// </summary>
        /// <param name="values">当前结点值</param>
        /// <param name="sql">查询所有记录的Sql语句</param>
        /// <param name="ParentFieldName">父ID字段名</param>
        /// <param name="KeyFieldName">主键字段名</param>
        /// <returns>主键字符串</returns>
        /// <example>
        /// private string GetChildrenDeparment(string departmentid)
        ///{
        ///    string sql = "select * from Department";
        ///    string DepartmentID = "DepartmentParent";
        ///    string KeyFieldName = "DepartmentID";
        ///    return GetChildren(departmentid, sql, ParentFieldName, KeyFieldName);
        ///}
        /// </example>
        public static string GetChildren(string values, string sql, string ParentFieldName, string KeyFieldName)
        {

            //根据Sql获得DataTable
            DataTable source = GetDataTableBySql(sql);

            //初始化结果字符串
            string result = "";

            //递归获取子串其它本身
            result = GetChildren(values, source, ParentFieldName, KeyFieldName);

            return result.Substring(0, result.Length - 1);
        }

        /// <summary>
        /// 递归获取子结点(包括自身结点)
        /// </summary>
        /// <param name="values">当前结点值</param>
        /// <param name="source">包括所有数据的数据源</param>
        /// <param name="ParentFieldName">父ID字段名</param>
        /// <param name="KeyFieldName">主键字段名</param>
        /// <returns>主键字符串</returns>
        private static string GetChildren(string values, DataTable source, string ParentFieldName, string KeyFieldName)
        {
            string children = values + ",";

            DataRow[] results = source.Select(ParentFieldName + "='" + values + "'");
            if (results.Length != 0)
            {
                foreach (DataRow dr in results)
                {
                    children += GetChildren(dr[KeyFieldName].ToString().Trim(), source, ParentFieldName, KeyFieldName);
                }

            }

            return children;
        }
        #endregion