using System.ServiceModel;

namespace BasicService
{
  [ServiceContract(Name="My First Indigo Service",
    Namespace="http://www.qacommunity.com/services",
    Session=true,
    CallbackContract=typeof(IOrderCallback))]
  public interface IOrderContract
  {
    [OperationContract(IsOneWay = true)]
    void PlaceOrder(Order order);
  }

  [ServiceContract(Name="My First Indigo Callback",
    Namespace="http://www.qacommunity.com/services")]
  public interface IOrderCallback 
  {
    [OperationContract(IsOneWay = true)]
    void PlaceOrderCompleted(OrderStatus orderStatus);
  }
}

using System.Runtime.Serialization;

namespace BasicService
{

  [DataContract(Name="OrderType")]
  public class Order
  {
    [DataMember]
    public string Description;

    [DataMember(Name="Quantity")]
    private int quantity;

    [DataMember(Name="Price")]
    double price;

    public int Quantity
    {
      get
      {
        return quantity;
      }
      set
      {
        quantity = value;
      }
    }

    public double Price
    {
      get
      {
        return price;
      }
      set
      {
        price = value;
      }
    }
  }

  [DataContract(Name="OrderStatusType")]
  public class OrderStatus
  {
    [DataMember]
    private string description;

    public string Description
    {
      get
      {
        return description;
      }
      set
      {
        description = value;
      }
    }
  }
}