C# Web Api GET POST json as custom string type

Question

With Put and Get request I receive empty strings for a field that should contain json string.

For example: I Put the following Json:

{
  "card": {
    "foo": "bar",
    "xyz": "dby"
  }
}

Now if the receiving class has a member of type JObject, then it is mapped correctly

public class contact {
     public int id { get; set; }
     public string name { get; set; }
     public JObject card { get; set; }
}

However if I change the type to a custom string type that can receive all JTokens:

public class contact {
      public int id { get; set; }
      public string name { get; set; }
      public JsonString card { get; set; } //**Changed HERE**//
    }

Then, the Put and Get method both show empty strings.

JsonString looks like as follows:

public class JsonString
{
        private string _json;

        public JsonString (string json)
        {
            this._json = json;
        }

        public string Value()
        {
            return _json;
        }

        public override int GetHashCode()
        {
            return _json.GetHashCode();
        }

        public override bool Equals(object obj)
        {
            return (obj is JsonString) && this.GetHashCode() == obj.GetHashCode();
        }
        public override string ToString()
        {
                return _json;
        }
}

The jsonString class more, but probably not needed in this context. Any idea why The put/Get are returning empty strings and how can I fix this?

EDIT:

The Put looks like this:

[HttpPut]
 [Route("contacts/{contactid}")]
 public HttpResponseMessage update(int id, contact c) {
 contact.update(c);
}

Answer 1

JObject looks like this:

public class JObject : JContainer, IDictionary<string, JToken>, 
ICollection<KeyValuePair<string, JToken>>, IEnumerable<KeyValuePair<string, JToken>>, 
IEnumerable, INotifyPropertyChanged, ICustomTypeDescriptor, INotifyPropertyChanging

What you've got is just a string, while JObject acts as a key-value datastucture.

You can't just map it like this. You might have better luck with dynamic object but still it is not that simple.