C# JsonConverter can convert properties depending on the class

Question

I want to write a JsonConverter it can convert a determinate property type but only depending on the class they are defined.

I am registering the JsonConverter globally via Web API:

var config = GlobalConfiguration.Configuration;
var jsonSettings = config.Formatters.JsonFormatter.SerializerSettings;
jsonSettings.Converters.Add(new SomeConverter());

The Converter can convert for example objects of type MyType.

public override bool CanConvert(Type objectType)
{
    return typeof(MyType).IsAssignableFrom(objectType);
}

But now I want to control want the converter should be used or not.

I thought something like that:

[IgnoreSomeConverter]
public class ClassA
{
    public MyType PropMyType {get;set;}
}

public class ClassB
{
    public MyType PropMyType {get;set;}
}

So I would like that the SomeConverter serialized and deserialized the properties MyType only when the property is defined in a class not decorated with the CustomAttribute IgnoreSomeConverter. In the example I want to use the converter for ClassB but not for ClassA. Any idea to get that?

Answer 1

Newtonsoft.JSON package contains DefaultContractResolver class, register it on your serializer settings, create a derived class from it, this you can adopt to class or a class property.

public class ShouldSerializeContractResolver : DefaultContractResolver
{
    protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
    {
        JsonProperty property = base.CreateProperty(member, memberSerialization);

        property.ShouldSerialize = i => false;
        property.Ignored = true;

        return property;
    }
}

And register it.

    var serializer = new JsonSerializerSettings { ContractResolver = new ShouldSerializeContractResolver() };

Function has MemberInfo argument from which you can attributes, etc.