將實體類或者集合序列化爲xml（xmlDataDocument）

         /// <summary>
        /// 將數據序列化爲Xml
        /// </summary>
        /// <param name="oType">被序列化的數據類型（實體類類型或者集合類型，如果爲集合類型則不要使用該集合類型的接口類型）</param>
        /// <param name="oData">數據對象</param>
        /// <returns></returns>
        private XmlDataDocument SerialiazerXmlDataDoc(Type oType, object oData)
        {
            XmlSerializer oXmlSerializer = new XmlSerializer(oType); //爲序列化器指定序列化類型
            MemoryStream oMemStream = new MemoryStream();

            oXmlSerializer.Serialize(oMemStream, oData); //爲序列化器指定要被序列化的數據

            XmlDataDocument oXmlDataDoc = new XmlDataDocument();
            oXmlDataDoc.LoadXml(System.Text.Encoding.UTF8.GetString(oMemStream.ToArray()));

          //將序列化的結果，轉換爲字符串加載進xmldatadocument對象

            return oXmlDataDoc;
        }