XML 转换为String 文本类型 显示中有换行显示

/// <summary>
        /// 将现有的文档转换为string
        /// </summary>
        /// <param name="strxml"></param>
        /// <returns></returns>
        private string xmlConvertString(XmlDocument xmldoc)
        {
            MemoryStream ms = new MemoryStream();
            xmldoc.Save(ms);
            StreamReader reader = new StreamReader(ms, Encoding.Default);
            reader.BaseStream.Seek(0, SeekOrigin.Begin);
            string str = reader.ReadLine();
            if (str != null)
            {
                str = reader.ReadToEnd();
            }
            return str;
        }