我们知道在.NET中我们有多种对象序列化的方式,如XML方式序列化、Binary序列化,其中XML序列化是一种比较通用的在各语言之间传递数据的方式。除了这两种序列化方式之外,在.NET中还可以使用JSON序列化。
JSON(JavaScript Object Notation)是一种轻量级轻量级的数据交换格式,并且它独立于编程语言,与XML序列化相比,JSON序列化后产生的数据一般要比XML序列化后数据体积小,所以在Facebook等知名网站中都采用了JSON作为数据交换方式。在.NET中有三种常用的JSON序列化的类,分别是 System.Web.Script.Serialization.JavaScriptSerializer类、System.Runtime.Serialization.Json.DataContractJsonSerializer类和Newtonsoft.Json.JsonConvert类。
为了便于下面的演示,下面提供一个类的代码:
[DataContract]
publicclass User
{
///<summary>
/// 编号
///</summary>
[DataMember]
publicint UserId { get; set; }
///<summary>
/// 用户名
///</summary>
[DataMember]
publicstring UserName { get; set; }
///<summary>
/// 创建时间
///</summary>
[DataMember]
[JsonConverter(typeof(IsoDateTimeConverter))]
public DateTime CreateDate { get; set; }
///<summary>
/// 生日
///</summary>
[DataMember]
[JsonConverter(typeof(JavaScriptDateTimeConverter))]
public DateTime Birthday { get; set; }
///<summary>
/// 相关URL
///</summary>
[DataMember]
public List<string> Urls { get; set; }
///<summary>
/// 薪水
///</summary>
//[ScriptIgnore]//使用JavaScriptSerializer序列化时不序列化此字段
//[IgnoreDataMember]//使用DataContractJsonSerializer序列化时不序列化此字段
//[JsonIgnore]//使用JsonConvert序列化时不序列化此字段
publicint Salary { get; set; }
///<summary>
/// 权利级别
///</summary>
[DataMember]
public Priority Priority { get; set; }
public User()
{
Urls =new List<string>();
}
}
///<summary>
/// 权利级别
///</summary>
publicenum Priority:byte
{
Lowest=0x1,
BelowNormal=0x2,
Normal=0x4,
AboveNormal=0x8,
Highest=0x16
}
使用System.Web.Script.Serialization.JavaScriptSerializer类
System.Web.Script.Serialization.JavaScriptSerializer类是.NET类库中自带的一种JSON序列化实现,在.NET Framework3.5及以后版本中可以使用这个类,这个类位于System.Web.Extensions.dll中,使用这个类是必须添加对这个dll的引用。
下面的代码是使用JavaScriptSerializer进行序列化和反序列化的例子:
publicstaticvoid JavaScriptSerializerDemo()
{
User user =new User { UserId =1, UserName ="李刚", CreateDate = DateTime.Now.AddYears(-30),Birthday=DateTime.Now.AddYears(-50), Priority = Priority.Highest, Salary =500000 };
//JavaScriptSerializer类在System.Web.Extensions.dll中,注意添加这个引用
JavaScriptSerializer serializer =new JavaScriptSerializer();
//JSON序列化
string result=serializer.Serialize(user);
Console.WriteLine("使用JavaScriptSerializer序列化后的结果:{0},长度:{1}", result, result.Length);
//JSON反序列化
user = serializer.Deserialize<User>(result);
Console.WriteLine("使用JavaScriptSerializer反序列化后的结果:UserId:{0},UserName: {1},CreateDate:{2},Priority:{3}", user.UserId, user.UserName, user.CreateDate, user.Priority);
}
说明:如果不想序列化某个字段,可以在字段前面加[JsonIgnore]标记。
使用System.Runtime.Serialization.Json.DataContractJsonSerializer类
System.Runtime.Serialization.Json.DataContractJsonSerializer类位于System.ServiceModel.Web.dll中,使用这个类时除了需要添加对System.ServiceModel.Web.dll的引用之外,还需要添加System.Runtime.Serialization.dll的引用,注意这个类也是在.NET Framework3.5及以后版本中可以使用。
下面是使用DataContractJsonSerializer类的例子:
publicstaticvoid DataContractJsonSerializerDemo()
{
User user =new User { UserId =1, UserName ="李刚", CreateDate = DateTime.Now.AddYears(-30), Birthday = DateTime.Now.AddYears(-50), Priority = Priority.AboveNormal, Salary =50000 };
string result =string.Empty;
//DataContractJsonSerializer类在System.ServiceModel.Web.dll中,注意添加这个引用
DataContractJsonSerializer serializer =new DataContractJsonSerializer(typeof(User));
using (MemoryStream stream =new MemoryStream())
{
//JSON序列化
serializer.WriteObject(stream, user);
result = Encoding.UTF8.GetString(stream.ToArray());
Console.WriteLine("使用DataContractJsonSerializer序列化后的结果:{0},长度:{1}", result, result.Length);
}
//JSON反序列化
byte[] buffer = Encoding.UTF8.GetBytes(result);
using (MemoryStream stream =new MemoryStream(buffer))
{
user = serializer.ReadObject(stream) as User;
Console.WriteLine("使用DataContractJsonSerializer反序列化后的结果:UserId: {0},UserName:{1},CreateDate:{2},Priority:{3}", user.UserId, user.UserName, user.CreateDate, user.Priority);
}
}
注意:要使用DataContractJsonSerializer类进行序列化和反序列化,必须给类加上[DataContract]属性,对要序列化的字段加上[DataMember]属性,如果不想序列化某个字段或者属性,可以加上[IgnoreDataMember]属性。
使用Newtonsoft.Json.JsonConvert类
Newtonsoft.Json.JsonConvert类是非微软提供的一个JSON序列化和反序列的开源免费的类库(下载网址是:http://www.codeplex.com/json/),它提供了更灵活的序列化和反序列化控制,并且如果你的开发环境使用的是.NET Framework3.5及以后版本的话,你就可以使用Linq to JSON,这样一来面对一大段的数据不必一一解析,你可以使用Linq to JSON解析出你关心的那部分即可,非常方便。
下面是使用Newtonsoft.Json.JsonConvert类的例子:
publicstaticvoid JsonConvertDemo()
{
User user =new User { UserId =1, UserName ="李刚", CreateDate = DateTime.Now.AddYears(-30), Birthday = DateTime.Now.AddYears(-50), Priority = Priority.BelowNormal, Salary =5000 };
//JsonConvert类在Newtonsoft.Json.Net35.dll中,注意到http://www.codeplex.com/json/下载这个dll并添加这个引用
//JSON序列化
string result = JsonConvert.SerializeObject(user);
Console.WriteLine("使用JsonConvert序列化后的结果:{0},长度:{1}", result, result.Length);
//JSON反序列化
user = JsonConvert.DeserializeObject<User>(result);
Console.WriteLine("使用JsonConvert反序列化后的结果:UserId:{0},UserName: {1},CreateDate:{2},Priority:{3}", user.UserId, user.UserName, user.CreateDate, user.Priority);
}
publicstaticvoid JsonConvertLinqDemo()
{
User user =new User { UserId =1, UserName ="周公", CreateDate = DateTime.Now.AddYears(-8), Birthday = DateTime.Now.AddYears(-32), Priority = Priority.Lowest, Salary =500, Urls =new List<string> { "http://zhoufoxcn.blog.51cto.com", "http://blog.csdn.net/zhoufoxcn" } };
//JsonConvert类在Newtonsoft.Json.Net35.dll中,注意到http://www.codeplex.com/json/下载这个dll并添加这个引用
//JSON序列化
string result = JsonConvert.SerializeObject(user);
Console.WriteLine("使用JsonConvert序列化后的结果:{0},长度:{1}", result, result.Length);
//使用Linq to JSON
JObject jobject = JObject.Parse(result);
JToken token = jobject["Urls"];
List<string> urlList =new List<string>();
foreach (JToken t in token)
{
urlList.Add(t.ToString());
}
Console.Write("使用Linq to JSON反序列化后的结果:[");
for (int i =0; i < urlList.Count -1;i++ )
{
Console.Write(urlList[i] +",");
}
Console.WriteLine(urlList[urlList.Count -1] +"]");
}
注意:如果有不需要序列化的字段,可以给该字段添加[JsonIgnore]标记。在Newtonsoft这个类库中对于日期的序列化有多种方式,可以类的DataTime成员添加上对应的标记,这样在进行序列化和反序列化时就会按照指定的方式进行,在本例中User类的CreateDate属性添加的属性是[JsonConverter(typeof(IsoDateTimeConverter))],而Birthday属性添加的属性是[JsonConverter(typeof(JavaScriptDateTimeConverter))],从序列化的结果可以看出来它们最终的表现形式并不一样。
本文中所有的示例代码如下:
1. using System;
2. using System.Collections.Generic;
3. using System.Linq;
4. using System.Text;
5. using System.Web.Script.Serialization;
6. using System.Runtime.Serialization.Json;
7. using System.IO;
8. using System.Runtime.Serialization;
9. using Newtonsoft.Json;
10. using Newtonsoft.Json.Linq;
11. using Newtonsoft.Json.Converters;
12.
13. namespace JSONDemo
14. {
15. class Program
16. {
17. staticvoid Main(string[] args)
18. {
19. JavaScriptSerializerDemo();
20. DataContractJsonSerializerDemo();
21. JsonConvertDemo();
22. JsonConvertLinqDemo();
23. Console.ReadLine();
24. }
25.
26. publicstaticvoid JavaScriptSerializerDemo()
27. {
28. User user =new User { UserId =1, UserName ="李刚", CreateDate = DateTime.Now.AddYears(-30),Birthday=DateTime.Now.AddYears(-50), Priority = Priority.Highest, Salary =500000 };
29. //JavaScriptSerializer类在System.Web.Extensions.dll中,注意添加这个引用
30. JavaScriptSerializer serializer =new JavaScriptSerializer();
31. //JSON序列化
32. string result=serializer.Serialize(user);
33. Console.WriteLine("使用JavaScriptSerializer序列化后的结果:{0},长度:{1}", result, result.Length);
34. //JSON反序列化
35. user = serializer.Deserialize<User>(result);
36. Console.WriteLine("使用JavaScriptSerializer反序列化后的结果:UserId:{0},UserName:{1},CreateDate:{2},Priority:{3}", user.UserId, user.UserName, user.CreateDate, user.Priority);
37.
38. }
39.
40. publicstaticvoid DataContractJsonSerializerDemo()
41. {
42. User user =new User { UserId =1, UserName ="李刚", CreateDate = DateTime.Now.AddYears(-30), Birthday = DateTime.Now.AddYears(-50), Priority = Priority.AboveNormal, Salary =50000 };
43. string result =string.Empty;
44. //DataContractJsonSerializer类在System.ServiceModel.Web.dll中,注意添加这个引用
45. DataContractJsonSerializer serializer =new DataContractJsonSerializer(typeof(User));
46.
47. using (MemoryStream stream =new MemoryStream())
48. {
49. //JSON序列化
50. serializer.WriteObject(stream, user);
51. result = Encoding.UTF8.GetString(stream.ToArray());
52. Console.WriteLine("使用DataContractJsonSerializer序列化后的结果:{0},长度:{1}", result, result.Length);
53. }
54.
55. //JSON反序列化
56. byte[] buffer = Encoding.UTF8.GetBytes(result);
57. using (MemoryStream stream =new MemoryStream(buffer))
58. {
59. user = serializer.ReadObject(stream) as User;
60. Console.WriteLine("使用DataContractJsonSerializer反序列化后的结果:UserId:{0},UserName:{1},CreateDate:{2},Priority:{3}", user.UserId, user.UserName, user.CreateDate, user.Priority);
61. }
62. }
63.
64. publicstaticvoid JsonConvertDemo()
65. {
66. User user =new User { UserId =1, UserName ="李刚", CreateDate = DateTime.Now.AddYears(-30), Birthday = DateTime.Now.AddYears(-50), Priority = Priority.BelowNormal, Salary =5000 };
67. //JsonConvert类在Newtonsoft.Json.Net35.dll中,注意到http://www.codeplex.com/json/下载这个dll并添加这个引用
68. //JSON序列化
69. string result = JsonConvert.SerializeObject(user);
70. Console.WriteLine("使用JsonConvert序列化后的结果:{0},长度:{1}", result, result.Length);
71. //JSON反序列化
72. user = JsonConvert.DeserializeObject<User>(result);
73. Console.WriteLine("使用JsonConvert反序列化后的结果:UserId:{0},UserName:{1},CreateDate:{2},Priority:{3}", user.UserId, user.UserName, user.CreateDate, user.Priority);
74. }
75.
76. publicstaticvoid JsonConvertLinqDemo()
77. {
78. User user =new User { UserId =1, UserName ="周公", CreateDate = DateTime.Now.AddYears(-8), Birthday = DateTime.Now.AddYears(-32), Priority = Priority.Lowest, Salary =500, Urls =new List<string> { "http://zhoufoxcn.blog.51cto.com", "http://blog.csdn.net/zhoufoxcn" } };
79. //JsonConvert类在Newtonsoft.Json.Net35.dll中,注意到http://www.codeplex.com/json/下载这个dll并添加这个引用
80. //JSON序列化
81. string result = JsonConvert.SerializeObject(user);
82. Console.WriteLine("使用JsonConvert序列化后的结果:{0},长度:{1}", result, result.Length);
83. //使用Linq to JSON
84. JObject jobject = JObject.Parse(result);
85. JToken token = jobject["Urls"];
86. List<string> urlList =new List<string>();
87. foreach (JToken t in token)
88. {
89. urlList.Add(t.ToString());
90. }
91. Console.Write("使用Linq to JSON反序列化后的结果:[");
92. for (int i =0; i < urlList.Count -1;i++ )
93. {
94. Console.Write(urlList[i] +",");
95. }
96. Console.WriteLine(urlList[urlList.Count -1] +"]");
97. }
98. }
99.
100. [DataContract]
101. publicclass User
102. {
103. ///<summary>
104. /// 编号
105. ///</summary>
106. [DataMember]
107. publicint UserId { get; set; }
108. ///<summary>
109. /// 用户名
110. ///</summary>
111. [DataMember]
112. publicstring UserName { get; set; }
113. ///<summary>
114. /// 创建时间
115. ///</summary>
116. [DataMember]
117. [JsonConverter(typeof(IsoDateTimeConverter))]
118. public DateTime CreateDate { get; set; }
119. ///<summary>
120. /// 生日
121. ///</summary>
122. [DataMember]
123. [JsonConverter(typeof(JavaScriptDateTimeConverter))]
124. public DateTime Birthday { get; set; }
125. ///<summary>
126. /// 相关URL
127. ///</summary>
128. [DataMember]
129. public List<string> Urls { get; set; }
130. ///<summary>
131. /// 薪水
132. ///</summary>
133. [ScriptIgnore]//使用JavaScriptSerializer序列化时不序列化此字段
134. [IgnoreDataMember]//使用DataContractJsonSerializer序列化时不序列化此字段
135. [JsonIgnore]//使用JsonConvert序列化时不序列化此字段
136. publicint Salary { get; set; }
137. ///<summary>
138. /// 权利级别
139. ///</summary>
140. [DataMember]
141. public Priority Priority { get; set; }
142.
143. public User()
144. {
145. Urls =new List<string>();
146. }
147. }
148. ///<summary>
149. /// 权利级别
150. ///</summary>
151. publicenum Priority:byte
152. {
153. Lowest=0x1,
154. BelowNormal=0x2,
155. Normal=0x4,
156. AboveNormal=0x8,
157. Highest=0x16
158. }
159. }
程序的运行结果如下:
- 使用JavaScriptSerializer序列化后的结果:{"UserId":1,"UserName":"李刚","CreateDate":"\/Date(353521211984)\/","Birthday":"\/Date(-277630788015)\/","Urls":[],"Priority":22},长度:127
- 使用JavaScriptSerializer反序列化后的结果:UserId:1,UserName:李刚,CreateDate:1981-3-15 16:20:11,Priority:Highest
- 使用DataContractJsonSerializer序列化后的结果:{"Birthday":"\/Date(-277630787953+0800)\/","CreateDate":"\/Date(353521212046+0800)\/","Priority":8,"Urls":[],"UserId":1,"UserName":"李刚"},长度:136
- 使用DataContractJsonSerializer反序列化后的结果:UserId:1,UserName:李刚,CreateDate:1981-3-16 0:20:12,Priority:AboveNormal
- 使用JsonConvert序列化后的结果:{"UserId":1,"UserName":"李刚","CreateDate":"1981-03-16T00:20:12.1875+08:00","Birthday":new Date(-277630787812),"Urls":[],"Priority":2},长度:132
- 使用JsonConvert反序列化后的结果:UserId:1,UserName:李刚,CreateDate:1981-3-16 0:20:12,Priority:BelowNormal
- 使用JsonConvert序列化后的结果:{"UserId":1,"UserName":"周公","CreateDate":"2003-03-16T00:20:12.40625+08:00","Birthday":new Date(290362812406),"Urls":["http://zhoufoxcn.blog.51cto.com","http://blog.csdn.net/zhoufoxcn"],"Priority":1},长度:198
- 使用Linq to JSON反序列化后的结果:["http://zhoufoxcn.blog.51cto.com","http://blog.csdn.net/zhoufoxcn"]
总结:通过上面的例子大家可以看出Newtonsoft类库提供的JSON序列化和反序列的方式更加灵活,在实际开发中周公也一直使用Newtonsoft作为JSON序列化和反序列化的不二选择。