//将DataTable转换成xml字符串:        public string ConvertDataTableToXml(DataTable dt)        {            MemoryStream stream = null;            XmlTextWriter writer = null;            try            {                stream = new MemoryStream();                writer = new XmlTextWriter(stream, System.Text.Encoding.Unicode);                dt.WriteXml(writer);                int count = (int)stream.Length;                byte[] arr = new byte[count];                stream.Seek(0, SeekOrigin.Begin);                stream.Read(arr, 0, count);                System.Text.Encoding ucode = System.Text.Encoding.Unicode;    //若使用utf-8，遇中文会发生乱码                return ucode.GetString(arr).Trim();            }            catch            {                return String.Empty;            }        }