使用Json.net仅将接口属性序列化为JSON

Question

使用像这样的简单类/接口

public interface IThing
{
    string Name { get; set; }
}

public class Thing : IThing
{
    public int Id { get; set; }
    public string Name { get; set; }
}

如何只使用"Name"属性(仅底层接口的属性)获取JSON字符串？

实际上,当我做到这一点时:

var serialized = JsonConvert.SerializeObject((IThing)theObjToSerialize, Formatting.Indented);
Console.WriteLine(serialized);

我得到完整的对象为JSON(Id + Name);

Answer 1

我用的方法,

public class InterfaceContractResolver : DefaultContractResolver
{
    private readonly Type _InterfaceType;
    public InterfaceContractResolver (Type InterfaceType)
    {
        _InterfaceType = InterfaceType;
    }

    protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
    {
        //IList<JsonProperty> properties = base.CreateProperties(type, memberSerialization);
        IList<JsonProperty> properties = base.CreateProperties(_InterfaceType, memberSerialization);
        return properties;
    }
}

// To serialize do this:
var settings = new JsonSerializerSettings() {
     ContractResolver = new InterfaceContractResolver (typeof(IThing))
});
string json = JsonConvert.SerializeObject(theObjToSerialize, settings);

Answer 2

灵感来自@ user3161686,这是一个小修改InterfaceContractResolver:

public class InterfaceContractResolver<TInterface> : DefaultContractResolver where TInterface : class
{
    protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
    {
        IList<JsonProperty> properties = base.CreateProperties(typeof(TInterface), memberSerialization);
        return properties;
    }
}

Answer 3

带有嵌套接口的改进版本+支持xsd.exe对象

这里还有另一种变化.代码来自http://www.tomdupont.net/2015/09/how-to-only-serialize-interface.html,其中的其他答案有以下改进

• 处理层次结构,因此如果你有一个Interface2[],Interface1那么它将被序列化.

• 我试图序列化一个WCF代理对象,结果JSON出现了{}.原来所有的属性都被设置为Ignore=true所以我不得不添加一个循环来将它们全部设置为不被忽略.

  public class InterfaceContractResolver : DefaultContractResolver
  {
      private readonly Type[] _interfaceTypes;
  
      private readonly ConcurrentDictionary<Type, Type> _typeToSerializeMap;
  
      public InterfaceContractResolver(params Type[] interfaceTypes)
      {
          _interfaceTypes = interfaceTypes;
  
          _typeToSerializeMap = new ConcurrentDictionary<Type, Type>();
      }
  
      protected override IList<JsonProperty> CreateProperties(
          Type type,
          MemberSerialization memberSerialization)
      {
          var typeToSerialize = _typeToSerializeMap.GetOrAdd(
              type,
              t => _interfaceTypes.FirstOrDefault(
                  it => it.IsAssignableFrom(t)) ?? t);
  
          var props = base.CreateProperties(typeToSerialize, memberSerialization);
  
          // mark all props as not ignored
          foreach (var prop in props)
          {
              prop.Ignored = false;
          }
  
          return props;
      }
  }
  

Answer 4

您可以使用条件序列化.看看这个链接.基本上,您需要实现IContractResolver接口,重载ShouldSerialize方法并将解析器传递给Json Serializer的构造函数.

Answer 5

[JsonIgnore]是[DataContract]和[DataMember]属性的替代方案.如果您使用[DataContract]序列化程序标记了类,则只处理使用该[DataMember]属性标记的属性("op-in" JsonIgnore是"选择退出"模型DataContract).

[DataContract]
public class Thing : IThing
{
    [DataMember]
    public int Id { get; set; }

    public string Name { get; set; }
}

这两种方法的局限在于它们必须在类中实现,不能将它们添加到接口定义中.

Answer 6

您可以添加[JsonIgnore]注释以忽略属性.