Problem with knowntype attribute in wcf

Question

I\'m having the following error in my wcf client.

NetDispatcherFaultException was unhandled.

The formatter threw an exception while trying

Answer 1

The following code work fine without error.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;

namespace WcfService1 {
    [ServiceKnownType(typeof(Car))]
    [ServiceKnownType(typeof(bike))]
    [ServiceKnownType(typeof(Kidsbike))]
    [ServiceContract]
    public interface IVehicleService {
        [OperationContract]
        Vehicle GetVehicle(int type);

        [OperationContract]
        int GetNumberOfWheels(Vehicle vehicle);
    }

      [DataContract]
    public abstract class Vehicle
    {
        [DataMember]
        public int ID { get; set; }

        abstract public int NoOfWheels { get; }
        [DataMember]
        public string Brand { get; set; }
    }
    [DataContract]
    public class Car : Vehicle
    {
        override public int NoOfWheels { get { return 0; } }
        [DataMember]
        public string SteeringWheelPosition { get; set; }
    }

    [KnownType(typeof(Kidsbike))]
    [DataContract]
    public class bike : Vehicle
    {
        override public int NoOfWheels { get { return 0; } }
        [DataMember]
        public bool HasFrontWheelBreak { get; set; }
    }
    [DataContract]
    public class Kidsbike : bike
    {
        [DataMember]
        public bool HasSupportingWheels { get; set; }
    }

[ServiceBehavior(AddressFilterMode = AddressFilterMode.Any)]   
public class VehicleService : IVehicleService
{        
    public Vehicle GetVehicle(int type)
    {
        switch (type)
        {
            case 0:
                return new Car()
                {
                   ID = 10,
                   Brand = "Volvo",
                   SteeringWheelPosition = "left"
                };

            case 1:
                return new bike()
                {
                    ID = 11,
                    Brand = "Scott",
                    HasFrontWheelBreak = true
                };

            case 2:
                return new Kidsbike()
                {
                    ID = 12,
                    Brand = "Kid Scott",
                    HasFrontWheelBreak = false,
                    HasSupportingWheels = true
                };

            default:
                return null;
        }
    }

    public int GetNumberOfWheels(Vehicle vehicle)
    {
        return vehicle.NoOfWheels;
    }
}

}

Svc file:

<%@ ServiceHost Language="C#" Debug="true" Service="WcfService1.VehicleService" CodeBehind="Service1.svc.cs" %>

Testing service:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ServiceModel;
using WcfService1;

namespace Test {
    class Program {
        static void Main(string[] args) {
            BasicHttpBinding hproxy = new BasicHttpBinding();
            hproxy.MaxReceivedMessageSize = 2147483647;
            hproxy.MaxBufferSize = 2147483647;
            hproxy.MaxBufferPoolSize = 2147483647;
            EndpointAddress eaddrr = new EndpointAddress("http://localhost:62807/Service1.svc");
            ChannelFactory CFactoryobj1 = new ChannelFactory(hproxy, eaddrr);
            IVehicleService isclientobj1 = CFactoryobj1.CreateChannel(); 
            Car ve = (Car)isclientobj1.GetVehicle(0);
        }
    }
}