string JsonStr= JsonConvert.SerializeObject(Entity);

eg:

A a=new A();

a.Name="Elain00";

a.Hobby="eat eat";

string jsonStr=JsonConvert.SerializeObject(a);

2.JSON反序列化

string jsonstr = "jsonString";
Class model = JsonConvert.DeserializeObject<Class>(jsonstr);

eg:

string JsonStr='"{\'Name\':\'Elaine00\',\'Hobby\':\'eat eat\'}";
A a=JsonConvert.DeserializeObject<A>(JsonStr);

3.时间格式处理

 IsoDateTimeConverter timeFormat = new IsoDateTimeConverter();
 timeFormat.DateTimeFormat = "yyyy-MM-dd HH:mm:ss";
 Response.Write(JsonConvert.SerializeObject(bll.GetModelList(strWhere), Newtonsoft.Json.Formatting.Indented, timeFormat));

4.扩展方法

public static class NewtonJSONHelper
 { public static string SerializeObject(this object obj)
 { return JsonConvert.SerializeObject(obj, Formatting.Indented, new JsonSerializerSettings{
 ReferenceLoopHandling = ReferenceLoopHandling.Ignore});
 } public static T DeserializeObject<T>(this string data)
 { return JsonConvert.DeserializeObject<T>(data, new JsonSerializerSettings
 {
 ReferenceLoopHandling = ReferenceLoopHandling.Ignore
 });
 }
 }

5.日期处理

public class LogEntry
{ public string Details { get; set; } public DateTime LogDate { get; set; }
}public void WriteJsonDates()
{
 LogEntry entry = new LogEntry
 {
 LogDate = new DateTime(2009, 2, 15, 0, 0, 0, DateTimeKind.Utc),
 Details = "Application started."
 }; // default as of Json.NET 4.5
 string isoJson = JsonConvert.SerializeObject(entry); // {"Details":"Application started.","LogDate":"2009-02-15T00:00:00Z"}
 JsonSerializerSettings microsoftDateFormatSettings = new JsonSerializerSettings
 {
 DateFormatHandling = DateFormatHandling.Micro

public class LimitPropsContractResolver : DefaultContractResolver
 { private string[] props = null; public LimitPropsContractResolver(string[] props)
 { this.props = props;
 } protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
 {
 IList<JsonProperty> list = base.CreateProperties(type, memberSerialization);
 IsoDateTimeConverter iso = new IsoDateTimeConverter() { DateTimeFormat = "yyyy-MM-dd HH:mm:ss" };
 IList<JsonProperty> listWithConver = new List<JsonProperty>(); foreach (var item in list)
 { if (props.Contains(item.PropertyName))
 { if (item.PropertyType.ToString().Contains("System.DateTime"))
 {
 item.Converter = iso;
 }
 listWithConver.Add(item);
 }
 } return listWithConver;
 }
 }
}

softDateFormat
 }; string microsoftJson = JsonConvert.SerializeObject(entry, microsoftDateFormatSettings); // {"Details":"Application started.","LogDate":"\/Date(1234656000000)\/"}

 string javascriptJson = JsonConvert.SerializeObject(entry, new JavaScriptDateTimeConverter()); // {"Details":"Application started.","LogDate":new Date(1234656000000)}}

2.JSON反序列化string jsonstr = "jsonString";
Class model = JsonConvert.DeserializeObject<Class>(jsonstr);

eg:string JsonStr='"{\'Name\':\'Elaine00\',\'Hobby\':\'eat eat\'}";A a=JsonConvert.DeserializeObject<A>(JsonStr);

一般是对于值类型的处理,通过设置jSetting.DefaultValueHandling的值来确定,该值为枚举类型.

DefaultValueHandling.Ignore

DefaultValueHandling.Include

给成员设置默任值,用到"DefaultValue(value)"特性,当然别忘了引入命名空间"System.ComponentModel",假设员工的年龄默认值为30

 [DefaultValue(30)]
 public int Age { get; set; }

序列化时我想忽略为默认值的成员

 Staff jack = new Staff { Name = "Jack", Age = 30, Gender = "Male", DepartmentName = "Personnel Department", Leader = null };
 var jSetting = new JsonSerializerSettings();
 jSetting.DefaultValueHandling = DefaultValueHandling.Ignore;
 string json = JsonConvert.SerializeObject(jack,jSetting);
 Console.WriteLine(json);

结果:

3.忽略某些属性

首先介绍Json.Net序列化的模式:OptOut 和 OptIn.

假如客户仅仅需要员工的姓名,此时

 [JsonObject(Newtonsoft.Json.MemberSerialization.OptIn)]
 public class Staff
 {
 [JsonProperty]
 public string Name { get; set; }
 public int Age { get; set; }
 public string Gender { get; set; }
 public string DepartmentName { get; set; }
 public Staff Leader { get; set; }
 }

序列化:

 Staff jack = new Staff { Name = "Jack", Age = 30, Gender = "Male", DepartmentName = "Personnel Department", Leader = null };
 string json = JsonConvert.SerializeObject(jack);

结果:

如果客户不想要员工的领导信息

 public class Staff
 {
 public string Name { get; set; }
 public int Age { get; set; }
 public string Gender { get; set; }
 public string DepartmentName { get; set; }
 [JsonIgnore]
 public Staff Leader { get; set; }
 }

序列化:

 Staff tom = new Staff { Name = "Tome", Age = 42, Gender = "Male", DepartmentName = "Personnel Department"};
 Staff jack = new Staff { Name = "Jack", Age = 30, Gender = "Male", DepartmentName = "Personnel Department", Leader = tom };
 string json = JsonConvert.SerializeObject(jack);
 Console.WriteLine(json);

结果:

4.支持非公共成员

Json.Net序列化对象时,默认情况下仅仅序列化公有成员,如果想要非公有成员也被序列化,就要在该成员上加特性"JsonProperty"

5.日期处理

　　JsonConverters会在序列化和反序列化时被用到。JsonConverters允许手动对Json的控制。当Json的结构很复杂和你想改变一个类型怎么样被序列化时，这是非常有用的。当一个JsonConverters被添加到JsonSerializer时，它会检查每一要被序列化和反序列化的值，并返回CanConvert，如果为True,则JsonConverter读和写这个值；需要注意的是，虽然JsonConverter能够使你可以完全的控制Json的值，但是很多的Json.Net序列化的特性被，像是类型名称和引用处理。所有的JsonConvert都在命名空间 "Newtonsoft.Json.Converters"下

5.1IsoDateTimeConverter 和 JavaScriptDateTimeConverter

这是Json.Net中自带的两个处理日期的类,默认是IsoDateTimeConverter ,它的格式是"yyyy'-'MM'-'dd'T'HH':'mm':'ss.FFFFFFFK".另一个是JavaScriptTimeConverter,它的格式是 "new Date(ticks)",其实返回的是一个JavaScript的Date对象.
有两种方式来应用JsonConverter,改变Json序列化和反序列化的行为.

5.1.1如果你要序列化的日期格式是统一的,可以考虑如下方式

假设我们为员工添加两个日期类型的成员,出生日期和入职日期

 public class Staff
 {
 public string Name { get; set; }
 public int Age { get; set; }
 public string Gender { get; set; }
 public string DepartmentName { get; set; }
 public Staff Leader { get; set; }
 public DateTime BirthDate { get; set; }
 public DateTime EmploymentDate { get; set; }
 }

我们的客户要求日期类型的成员返回javascript的日期对象

 Staff jack = new Staff { Name = "Jack", Age = 30, Gender = "Male",
 DepartmentName = "Personnel Department", BirthDate = new DateTime(1982,2,12), EmploymentDate = new DateTime(2010,12,12) };
 string json = JsonConvert.SerializeObject(jack,new JavaScriptDateTimeConverter());
 Console.WriteLine(json);

结果:

5.1.2如果想要不同的日期类型成员序列化后,以不同的形式显示.

现在我们的客户要求出生日期以"ISO"标准日期格式返回,入职日期以Javascript的Date对象格式返回,修改我们的员工类

 public class Staff
 {
 public string Name { get; set; }
 public int Age { get; set; }
 public string Gender { get; set; }
 public string DepartmentName { get; set; }
 public Staff Leader { get; set; }
 [JsonConverter(typeof(IsoDateTimeConverter))]
 public DateTime BirthDate { get; set; }
 [JsonConverter(typeof(JavaScriptDateTimeConverter))]
 public DateTime EmploymentDate { get; set; }
 }

是的,通过特性"JsonConverter"来实现差异化的
序列化:

 Staff jack = new Staff { Name = "Jack", Age = 30, Gender = "Male",
 DepartmentName = "Personnel Department", BirthDate = new DateTime(1982,2,12), EmploymentDate = new DateTime(2010,12,12) };
 string json = JsonConvert.SerializeObject(jack);
 Console.WriteLine(json);

结果:

5.2自定义日期格式

客户现在提出要求,希望得到的日期格式是符合中国人习惯的格式.要求返回的格式是"2012年4月20日".挑战来了,没有挑战就没有进步,我喜欢挑战.光说是没有用的!先分析一下怎么解决这个问题.我考虑了两种思路.
　　思路一:
研究了一下上面两个日期处理类,发现他们都是继承了基类"DateTimeConverterBase",所以我们可以参考"IsoDatetimeConverter"的实现方式,自己新建一个处理日期格式的转换器类.这种方式的缺点是可能要花大量的时间去研究,比较费时费力.优点就是可以对日期格式随心所欲的控制.
　　思路二:
我又研究了一下"IsoDatetimeConverter",发现它的日期格式其实是由于内部DefaultDateTimeFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ss.FFFFFFFK"导致,而它也提供了修改日期样式的属性"DateTimeFormat",只要我们按照这种格式来写就OK了.

 Staff jack = new Staff { Name = "Jack", Age = 30, Gender = "Male",
 DepartmentName = "Personnel Department", BirthDate = new DateTime(1982,2,12), EmploymentDate = new DateTime(2010,12,12) };
 IsoDateTimeConverter dtConverter = new IsoDateTimeConverter { DateTimeFormat = "yyyy'年'MM'月'dd'日'" };
 string json = JsonConvert.SerializeObject(jack,dtConverter);
 Console.WriteLine(json);

结果:

6.FAQ

1.如何自定义序列化的字段名称?

默认情况下,Json.Net序列化后结果中的字段名称和类中属性的名称一致.如果想自定义序列化后的字段名称,可以使用JsonProperty.例如：

 public class Person
 {
 public int Id { get; set; }

 public string Name { get; set; }
 }

默认序列化的结果为: {"Id":1,"Name":"杨过"},如果不想用默认的字段名称，可以使用如下方式：

public class Person
{
 [JsonProperty(PropertyName = "PersonId")]
 public int Id { get; set; }

 [JsonProperty(PropertyName = "PersonName")]
 public string Name { get; set; }
}

这样序列化的结果为：{"PersonId":1,"PersonName":"杨过"}