You need to remove the [DataContract]
attribute because this attribute tells the serializer that you will specify the fields to include for serialization using the [DataMember]
attribute, but you haven't done so.
Or alternatively mark your properties with [DataMember]
.
[DataContract]
[Route("/PiecParametrySzczegolowe")]
public class PiecParametrySzczegoloweRequest : IReturn<PiecParametrySzczegoloweResponse>
{
[DataMember]
public bool Initialize { get; set; }
[DataMember]
public PiecParametrySzczegoloweLegend Config { get; set; }
[DataMember]
public int Percent { get; set; }
}