最近做的一个ASP.NET项目中,需要在一个页面中维护一个类的数组,在每次页面刷新的使其前一次的状态保持不变。开始错误的使用了static,导致了致命的共享错误。后来突然想起C#类能够使用XML序列化出来,然后保存在XML里或者保存在页面的一个隐藏表单里(稍后再比较这两种方法的优劣)。下面来介绍这两个类序列化的应用。
保存于XML中的序列化C#类
先声明那个需要保存的类如下:
1 [Serializable]
2 public class HalfHour
3 {
4 public string ibtnHalfHourName;
5 public int status;
6 public bool isFirst;
7 public int eventID;
8 public bool isHead;
9
10 public HalfHour()
11 {
12 this.ibtnHalfHourName = "";
13 this.status = HalfHour.BLANK;
14 this.isFirst = false;
15 this.eventID = -1;
16 this.isHead = false;
17 }
18
19 }
2 public class HalfHour
3 {
4 public string ibtnHalfHourName;
5 public int status;
6 public bool isFirst;
7 public int eventID;
8 public bool isHead;
9
10 public HalfHour()
11 {
12 this.ibtnHalfHourName = "";
13 this.status = HalfHour.BLANK;
14 this.isFirst = false;
15 this.eventID = -1;
16 this.isHead = false;
17 }
18
19 }
然后为这个类分别定义一个Serial和Deserial两个方法,分别完成序列化和反序列化这两件事(必要的namespace是System.Xml.Serialization和System.IO):
1 public static void Serial(HalfHour[] halfHours, string path)
2 {
3 XmlSerializer xmlSerializer = new XmlSerializer(typeof(HalfHour[]));
4 TextWriter writer = new StreamWriter(path);
5 try
6 {
7 xmlSerializer.Serialize(writer, halfHours);
8 }
9 finally
10 {
11 writer.Close();
12 }
13 }
14
15 public static HalfHour[] Deserial(string path)
16 {
17 XmlSerializer xmlSerializer = new XmlSerializer(typeof(HalfHour[]));
18 FileStream fs = new FileStream(path, FileMode.Open);
19 HalfHour[] halfHours;
20 try
21 {
22 halfHours = (HalfHour[])xmlSerializer.Deserialize(fs);
23 }
24 finally
25 {
26 fs.Close();
27 }
28 return halfHours;
29 }
2 {
3 XmlSerializer xmlSerializer = new XmlSerializer(typeof(HalfHour[]));
4 TextWriter writer = new StreamWriter(path);
5 try
6 {
7 xmlSerializer.Serialize(writer, halfHours);
8 }
9 finally
10 {
11 writer.Close();
12 }
13 }
14
15 public static HalfHour[] Deserial(string path)
16 {
17 XmlSerializer xmlSerializer = new XmlSerializer(typeof(HalfHour[]));
18 FileStream fs = new FileStream(path, FileMode.Open);
19 HalfHour[] halfHours;
20 try
21 {
22 halfHours = (HalfHour[])xmlSerializer.Deserialize(fs);
23 }
24 finally
25 {
26 fs.Close();
27 }
28 return halfHours;
29 }
这两个函数的调用应该很容易理解:对于Serial,你只需提供XML的保存路径和你需要序列化的那个类数组。而Deserial则只需要提供读取的XML路径即可。
保存于隐藏表单中的序列化C#类
要序列化的类的声明和上面一致,这里不再重复。但你需要在你的Web页面中定义你的隐藏表单。
下面是Serial和Deserial函数的重载版本,这里要引入System.Text的namespace:
1 public static string Serial(HalfHour[] halfHours)
2 {
3 XmlSerializer xmlSerializer = new XmlSerializer(typeof(HalfHour[]));
4 MemoryStream memoryStream = new MemoryStream();
5 xmlSerializer.Serialize(memoryStream, halfHours);
6 return Encoding.UTF8.GetString(memoryStream.GetBuffer());
7 }
8
9 public static HalfHour[] Deserial(string serialedObject)
10 {
11 XmlSerializer xmlSerializer = new XmlSerializer(typeof(HalfHour[]));
12 MemoryStream memoryStream = new MemoryStream(Encoding.UTF8.GetBytes(serialedObject));
13 return (HalfHour[])xmlSerializer.Deserialize(memoryStream);
14 }
2 {
3 XmlSerializer xmlSerializer = new XmlSerializer(typeof(HalfHour[]));
4 MemoryStream memoryStream = new MemoryStream();
5 xmlSerializer.Serialize(memoryStream, halfHours);
6 return Encoding.UTF8.GetString(memoryStream.GetBuffer());
7 }
8
9 public static HalfHour[] Deserial(string serialedObject)
10 {
11 XmlSerializer xmlSerializer = new XmlSerializer(typeof(HalfHour[]));
12 MemoryStream memoryStream = new MemoryStream(Encoding.UTF8.GetBytes(serialedObject));
13 return (HalfHour[])xmlSerializer.Deserialize(memoryStream);
14 }
两种方式的比较
选择文件读写方式显然在服务器运行速度上会比较慢,而且要构思不产生冲突的文件名,同时还要考虑文件系统的读写权限问题。写入表单则没有这个问题,但是如果序列化的对象过大的话,会是整个页面文件变得很大,造成传输过程的缓慢。所以建议如果要序列化的对象较小,则选择后者。反之则选择前者。