How can I change property names when serializing w

Question

I have some data in a C# DataSet object. I can serialize it right now using a Json.net converter like this

DataSet data = new DataSet();
// do some work here to populate 'data'
string output = JsonConvert.SerializeObject(data);

However, this uses the property names from data when printing to the .json file. I would like to change the property names to be something different (say, change 'foo' to 'bar').

In the Json.net documentation, under 'Serializing and Deserializing JSON' → 'Serialization Attributes' it says "JsonPropertyAttribute... allows the name to be customized". But there is no example. Does anyone know how to use a JsonPropertyAttribute to change the property name to something else?

(Direct link to documentation)

Json.net's documentation seems to be sparse. If you have a great example I'll try to get it added to the official documentation. Thanks!

Answer 1

You could decorate the property you wish controlling its name with the [JsonProperty] attribute which allows you to specify a different name:

using Newtonsoft.Json;
// ...

[JsonProperty(PropertyName = "FooBar")]
public string Foo { get; set; }

Documentation: Serialization Attributes

Answer 2

There is still another way to do it, which is using a particular NamingStrategy, which can be applied to a class or a property by decorating them with [JSonObject] or [JsonProperty].

There are predefined naming strategies like CamelCaseNamingStrategy, but you can implement your own ones.

Answer 3

If you dont have access to the classes to change the properties, or dont want to always use the same rename property, renaming can also be done by creating a custom resolver.

For example, if you have a class called MyCustomObject, that has a property called LongPropertyName, you can use a custom resolver like this...

public class CustomDataContractResolver : DefaultContractResolver
{
  public static readonly CustomDataContractResolver Instance = new CustomDataContractResolver ();

  protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
  {
    var property = base.CreateProperty(member, memberSerialization);
    if (property.DeclaringType == typeof(MyCustomObject))
    {
      if (property.PropertyName.Equals("LongPropertyName", StringComparison.OrdinalIgnoreCase))
      {
        property.PropertyName = "Short";
      }
    }
    return property;
  }
}

Then call for serialization and supply the resolver

 var result = JsonConvert.SerializeObject(myCustomObjectInstance,
                new JsonSerializerSettings { ContractResolver = CustomDataContractResolver.Instance });

And the result will be shortened to {"Short":"prop value"} instead of {"LongPropertyName":"prop value"}

More info on custom resolvers here