DataContract：Order & OrderItem
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.Serialization;
namespace Artech.QueuedService.Contract
{
[DataContract]
[KnownType(typeof(OrderItem))]
public class Order
{
Private Fields#region Private Fields
private Guid _orderNo;
private DateTime _orderDate;
private Guid _supplierID;
private string _supplierName;
private IList _orderItems;
#endregion
Constructors#region Constructors
public Order()
{
this._orderItems = new List();
}
public Order(Guid orderNo, DateTime orderDate, 
Guid supplierID, string supplierName)
{
this._orderNo = orderNo;
this._orderDate = orderDate;
this._supplierID = supplierID;
this._supplierName = supplierName;
this._orderItems = new List();
}
#endregion
Public Properties#region Public Properties
[DataMember]
public Guid OrderNo
{
get { return _orderNo; }
set { _orderNo = value; }
}
[DataMember]
public DateTime OrderDate
{
get { return _orderDate; }
set { _orderDate = value; }
}
[DataMember]
public Guid SupplierID
{
get { return _supplierID; }
set { _supplierID = value; }
}
[DataMember]
public string SupplierName
{
get { return _supplierName; }
set { _supplierName = value; }
}
[DataMember]
public IList OrderItems
{
get { return _orderItems; }
set { _orderItems = value; }
}
#endregion
Public Methods#region Public Methods
public override string ToString()
{
string description = string.Format("General Informaion:\n\tOrder No.\t: {0}\n\tOrder 
Date\t: {1}\n\tSupplier No.\t: {2}\n\tSupplier Name\t: {3}", this._orderNo, this._orderDate.
ToString("yyyy/MM/dd"), this._supplierID, this._supplierName);
StringBuilder productList = new StringBuilder();
productList.AppendLine("\nProducts:");
int index = 0;
foreach (OrderItem item in this._orderItems)
{
productList.AppendLine(string.Format("\n{4}. \tNo.\t\t: {0}\n\tName\t\t: 
{1}\n\tPrice\t\t: {2}\n\tQuantity\t: {3}", item.ProductID, item.ProductName, item.UnitPrice, 
item.Quantity, ++index));
}
return description + productList.ToString();
}
#endregion
}
}