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]
public class User
{
/// <summary>
/// 编号
/// </summary>
[DataMember]
public int UserId { get; set; }
/// <summary>
/// 用户名
/// </summary>
[DataMember]
public string 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
public int 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>
public enum 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:
public static void 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:
public static void 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:
public static void 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);
}
public static void 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:
- using System;
- using System.Collections.Generic;
- using System.Linq;
- using System.Text;
- using System.Web.Script.Serialization;
- using System.Runtime.Serialization.Json;
- using System.IO;
- using System.Runtime.Serialization;
- using Newtonsoft.Json;
- using Newtonsoft.Json.Linq;
- using Newtonsoft.Json.Converters;
- namespace JSONDemo
- {
- class Program
- {
- static void Main(string[] args)
- {
- JavaScriptSerializerDemo();
- DataContractJsonSerializerDemo();
- JsonConvertDemo();
- JsonConvertLinqDemo();
- Console.ReadLine();
- }
- public static void 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);
- }
- public static void 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);
- }
- }
- public static void 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);
- }
- public static void 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] + "]");
- }
- }
- [DataContract]
- public class User
- {
- /// <summary>
- /// 编号
- /// </summary>
- [DataMember]
- public int UserId { get; set; }
- /// <summary>
- /// 用户名
- /// </summary>
- [DataMember]
- public string 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
- public int 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>
- public enum Priority:byte
- {
- Lowest=0x1,
- BelowNormal=0x2,
- Normal=0x4,
- AboveNormal=0x8,
- Highest=0x16
- }
- }
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。
本文出自 “周公(周金桥)的专栏” 博客, 出处http://zhoufoxcn.blog.51cto.com/792419/517093
在.NET使用JSON作为数据交换格式(转)