Json net serialize deserialize derived types

Question

json net  newtonsoft  I am looking through the documentation but I can t find anything on this or the best way to do it   public class Base       public string Name    public class Derived   Base       public string Something     JsonConvert Deserialize lt List lt Base gt  gt  text     Now I have Derived objects in the serialized list  How do I deserialize the list and get back derived types

User · Answer

You have to enable Type Name Handling and pass that to the (de)serializer as a settings parameter.

Base object1 = new Base() { Name = "Object1" };
Derived object2 = new Derived() { Something = "Some other thing" };
List<Base> inheritanceList = new List<Base>() { object1, object2 };

JsonSerializerSettings settings = new JsonSerializerSettings { TypeNameHandling = TypeNameHandling.All };
string Serialized = JsonConvert.SerializeObject(inheritanceList, settings);
List<Base> deserializedList = JsonConvert.DeserializeObject<List<Base>>(Serialized, settings);

This will result in correct deserialization of derived classes. A drawback to it is that it will name all the objects you are using, as such it will name the list you are putting the objects in.

User · Answer

Use this JsonKnownTypes  it s very similar way to use  it just add discriminator to json    JsonConverter typeof JsonKnownTypeConverter lt BaseClass gt      JsonKnownType typeof Base    base     JsonKnownType typeof Derived    derived    public class Base       public string Name    public class Derived   Base       public string Something      Now when you serialize object in json will be add   type  with  base  and  derived  value and it will be use for deserialize  Serialized list example           Name   some name     type   base          Name   some name    Something   something     type   derived

User · Answer

If you are storing the type in your text  as you should be in this scenario   you can use the JsonSerializerSettings   See  how to deserialize JSON into IEnumerable lt BaseType gt  with Newtonsoft JSON NET  Be careful  though  Using anything other than TypeNameHandling   TypeNameHandling None could open yourself up to a security vulnerability

User · Answer

Since the question is so popular  it may be useful to add on what to do if you want to control the type property name and its value   The long way is to write custom JsonConverters to handle  de serialization by manually checking and setting the type property   A simpler way is to use JsonSubTypes  which handles all the boilerplate via attributes    JsonConverter typeof JsonSubtypes    Sound     JsonSubtypes KnownSubType typeof Dog    Bark     JsonSubtypes KnownSubType typeof Cat    Meow    public class Animal       public virtual string Sound   get        public string Color   get  set       public class Dog   Animal       public override string Sound   get       Bark       public string Breed   get  set       public class Cat   Animal       public override string Sound   get       Meow       public bool Declawed   get  set

[c#] Json.net serialize/deserialize derived types?

Examples related to c#

Examples related to json

Examples related to serialization

Examples related to json.net