将DataTable转换成xml字符串

　　　　　　//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;
            }
        }