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   
   
    }

 


 

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:

 

使用System.Web.Script.Serialization.JavaScriptSerializer类





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", "" } };   
  
        //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", "" } };   
  
            //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",""],"Priority":1},长度:198  
    使用Linq to JSON反序列化后的结果:["http://zhoufoxcn.blog.51cto.com",""] 



 

 

 



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。