unity3d xml序列化

using UnityEngine;
using System.Collections;
using System.Xml;
using System.Xml.Serialization;
using System.IO;
using System.Text;   

public class Reward
 {
   public Task task;
   public Attribute attribute;
   public Reward () {}
   public struct Task
   {
      [XmlAttribute("taskNo")]
      public int taskNo{ get; set;}
      [XmlAttribute("taskReward")]
      public int taskReward{ get; set;}
      public Id id1;
      public Id id2;
           public Id id3;
   }
   public struct Id
   {
      [XmlAttribute("flag")]
      public bool flag{ get; set;}
      [XmlAttribute("name")]
      public string name{ get; set;}
   }
}  

public class AchievementManager: MonoBehaviour {
   Reward reward ;
   FileInfo t ;
   string _data;
   void Start ()
   {
    reward = new Reward();
   t = new FileInfo(Application.dataPath+"\\"+ "Achievement.xml");
   LoadXML();
   reward.task.id1.name = "杨纯/nate";
   reward.task.id2.name = "有点笨";
   reward.task.id3.name = "dlnuchunge";
   Save();
   }   

   void LoadXML()
   {
      if(t.Exists)
      {
          StreamReader r = t.OpenText();
          string _info = r.ReadToEnd();
          r.Close();
          _data=_info;
          if(_data.ToString() != "")
          {
            reward = (Reward)DeserializeObject(_data);
          }
      }
   }
   public void Save()
   {
      _data = SerializeObject(reward);
      StreamWriter writer;
      if(t.Exists)
      {
         t.Delete();
      }
      writer = t.CreateText();
      writer.Write(_data);
      writer.Close();
   }
   string UTF8ByteArrayToString(byte[] characters)
   {
      UTF8Encoding encoding = new UTF8Encoding();
      string constructedString = encoding.GetString(characters);
      return (constructedString);
   }   

   byte[] StringToUTF8ByteArray(string pXmlString)
   {
      UTF8Encoding encoding = new UTF8Encoding();
      byte[] byteArray = encoding.GetBytes(pXmlString);
      return byteArray;
   }   

   // Here we serialize our Reward object of reward
   string SerializeObject(object pObject)
   {
      string XmlizedString = null;
      MemoryStream memoryStream = new MemoryStream();
      XmlSerializer xs = new XmlSerializer(typeof(Reward));
      XmlTextWriter xmlTextWriter = new XmlTextWriter(memoryStream, Encoding.UTF8);
      xs.Serialize(xmlTextWriter, pObject);
      memoryStream = (MemoryStream)xmlTextWriter.BaseStream;
      XmlizedString = UTF8ByteArrayToString(memoryStream.ToArray());
      return XmlizedString;
   }   

   // Here we deserialize it back into its original form
   object DeserializeObject(string pXmlizedString)
   {
      XmlSerializer xs = new XmlSerializer(typeof(Reward));
      MemoryStream memoryStream = new MemoryStream(StringToUTF8ByteArray(pXmlizedString));
      XmlTextWriter xmlTextWriter = new XmlTextWriter(memoryStream, Encoding.UTF8);
      return xs.Deserialize(memoryStream);
   }
}