Is there something like the opposite of a JsonIgnore?

Question

The JsonIgnore attribute can be used to ignore certain properties in serialization. I was wondering if it is possible to do the opposite of that? So a JsonSeria

Answer 1

Yes there is. When you mark your class with [JsonObjectAttribute] and pass the MemberSerialization.OptIn parameter, member serialization is opt-in. Then mark your members with [JsonProperty] to include them for serialization.

[JsonObject(MemberSerialization.OptIn)]
public class Person
{
    [JsonProperty]
    public string Name { get; set; }

    // not serialized because mode is opt-in
    public string Department { get; set; }
}

Answer 2

An alternative to MemberSerialization.OptIn is using DataContract/DataMember attributes:

[DataContract]
public class Computer
{
  // included in JSON
  [DataMember]
  public string Name { get; set; }
  [DataMember]
  public decimal SalePrice { get; set; }

  // ignored
  public string Manufacture { get; set; }
  public int StockCount { get; set; }
  public decimal WholeSalePrice { get; set; }
  public DateTime NextShipmentDate { get; set; }
}

Source: http://james.newtonking.com/archive/2009/10/23/efficient-json-with-json-net-reducing-serialized-json-size