Building_Extensible_WCF_Service_Interfaces_With_DataContractResolver_1.cs

public interface IScheduledTask
{
    [DataMember]
    Guid TaskId { get; set; }
}

// This is a generic implementation of IScheduledTask.
[DataContract]
public class ScheduledTask<T> : IScheduledTask
{
    [DataMember]
    public Guid TaskId { get; set; }

    [DataMember]
    public T Value { get; set; }

    public static implicit operator T(ScheduledTask<T> that)
    {
        return that.Value;
    }
}

// This is our service contract which takes IScheduledTask.
[ServiceContract(Namespace = "http://ServiceLib.TaskService")]
public interface IScheduledTaskService
{
    [OperationContract(IsOneWay = true)]
    void Submit(IScheduledTask task);
}

// This is our actual service implementation.
[ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)]
public class ScheduledTaskService : IScheduledTaskService
{
    public void Submit(IScheduledTask task)
    {
        Console.WriteLine("We got a task!");
    }
}