序列化为xml

private static string SerializeToXml(object obj, string encoding)
        {
            if (obj != null)
            {
                XmlSerializerNamespaces ns = new XmlSerializerNamespaces();
                ns.Add("", "");


                XmlSerializer serializer = new XmlSerializer(obj.GetType());
                MemoryStream ms = new MemoryStream();
                XmlTextWriter xtw = new XmlTextWriter(ms, System.Text.Encoding.GetEncoding(encoding));
                xtw.Formatting = Formatting.Indented;
                serializer.Serialize(xtw, obj, ns);

                ms.Seek(0, SeekOrigin.Begin);
                StreamReader sr = new StreamReader(ms, System.Text.Encoding.GetEncoding(encoding));
                string str = sr.ReadToEnd();
                xtw.Close();
                ms.Close();
                return str;
            }
            return string.Empty;
        }