如何：使用反射提供程序创建数据服务（WCF 数据服务）

使用 WCF 数据服务 可以定义基于任意类的数据模型，前提是这些类作为实现 IQueryable 接口的对象公开。 有关更多信息，请参见数据服务提供程序（WCF 数据服务）。

示例

下面的示例定义一个包括 Orders 和 Items 的数据模型。 实体容器类 OrderItemData 具有两个公共方法，这两个方法返回 IQueryable 接口。 这些接口是 Orders 和 Items 实体类型的实体集。 Order 可以包括多个 Items，因此 Orders 实体类型具有一个返回 Items 对象集合的 Items 导航属性。 OrderItemData 实体容器类是 OrderItems 数据服务派生自的 DataService 类的泛型类型。

注意：
由于此示例演示内存中数据提供程序，且未在当前对象实例外保存更改，因此实现 IUpdatable 接口不会带来任何好处。有关实现 IUpdatable 接口的示例，请参见如何：使用 LINQ to SQL 数据源创建数据服务（WCF 数据服务）。

Imports System
Imports System.Collections.Generic
Imports System.Data.Services
Imports System.Data.Services.Common
Imports System.Linq

Namespace CustomDataServiceClient
    <DataServiceKeyAttribute("OrderId")> _
    Public Class Order
        Private _orderId As Integer
        Private _customer As String
        Private _items As IList(Of Item)
        Public Property OrderId() As Integer
            Get
                Return _orderId
            End Get
            Set(ByVal value As Integer)
                _orderId = value
            End Set
        End Property
        Public Property Customer() As String
            Get
                Return _customer
            End Get
            Set(ByVal value As String)
                _customer = value
            End Set
        End Property
        Public Property Items() As IList(Of Item)
            Get
                Return _items
            End Get
            Set(ByVal value As IList(Of Item))
                _items = value
            End Set
        End Property
    End Class
    <EntityPropertyMappingAttribute("Product", "productname", _
        "orders", "http://schema.examples.microsoft.com/dataservices", True)> _
    <DataServiceKeyAttribute("Product")> _
    Public Class Item
        Private _product As String
        Private _quantity As Integer
        Public Property Product() As String
            Get
                Return _product
            End Get
            Set(ByVal value As String)
                _product = value
            End Set
        End Property
        Public Property Quantity() As Integer
            Get
                Return _quantity
            End Get
            Set(ByVal value As Integer)
                _quantity = value
            End Set
        End Property
    End Class
    Partial Public Class OrderItemData
#Region "Populate Service Data"
        Shared _orders As IList(Of Order)
        Shared _items As IList(Of Item)
        Sub New()
            _orders = New Order() { _
                New Order() With {.OrderId = 0, .Customer = "Peter Franken", .Items = New List(Of Item)()}, _
              New Order() With {.OrderId = 1, .Customer = "Ana Trujillo", .Items = New List(Of Item)()}}
            _items = New Item() { _
              New Item() With {.Product = "Chai", .Quantity = 10}, _
              New Item() With {.Product = "Chang", .Quantity = 25}, _
              New Item() With {.Product = "Aniseed Syrup", .Quantity = 5}, _
              New Item() With {.Product = "Chef Anton's Cajun Seasoning", .Quantity = 30}}
            _orders(0).Items.Add(_items(0))
            _orders(0).Items.Add(_items(1))
            _orders(1).Items.Add(_items(2))
            _orders(1).Items.Add(_items(3))
        End Sub
#End Region
        Public ReadOnly Property Orders() As IQueryable(Of Order)
            Get
                Return _orders.AsQueryable()
            End Get
        End Property
        Public ReadOnly Property Items() As IQueryable(Of Item)
            Get
                Return _items.AsQueryable()
            End Get
        End Property
    End Class
    Public Class OrderItems
        Inherits DataService(Of OrderItemData)
        ' This method is called only once to initialize
        ' service-wide policies.
        Shared Sub InitializeService(ByVal config As DataServiceConfiguration)
            config.SetEntitySetAccessRule("Orders", EntitySetRights.All)
            config.SetEntitySetAccessRule("Items", EntitySetRights.All)
            config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2
        End Sub
    End Class
End Namespace

using System;
using System.Collections.Generic;
using System.Data.Services;
using System.Data.Services.Common;
using System.Linq;

namespace CustomDataServiceClient
{
    [DataServiceKeyAttribute("OrderId")]
    public class Order
    {
        public int OrderId { get; set; }
        public string Customer { get; set; }
        public IList<Item> Items { get; set; }
    }
    [DataServiceKeyAttribute("Product")]
    public class Item
    {
        public string Product { get; set; }
        public int Quantity { get; set; }
    }
    public partial class OrderItemData
    {
        #region Populate Service Data
        static IList<Order> _orders;
        static IList<Item> _items;
        static OrderItemData()
        {
            _orders = new Order[]{
              new Order(){ OrderId=0, Customer = "Peter Franken", Items = new List<Item>()},
              new Order(){ OrderId=1, Customer = "Ana Trujillo", Items = new List<Item>()}};
            _items = new Item[]{
              new Item(){ Product="Chai", Quantity=10 },
              new Item(){ Product="Chang", Quantity=25 },
              new Item(){ Product="Aniseed Syrup", Quantity = 5 },
              new Item(){ Product="Chef Anton's Cajun Seasoning", Quantity=30}};
            _orders[0].Items.Add(_items[0]);
            _orders[0].Items.Add(_items[1]);
            _orders[1].Items.Add(_items[2]);
            _orders[1].Items.Add(_items[3]);
        }
        #endregion
        public IQueryable<Order> Orders
        {
            get { return _orders.AsQueryable<Order>(); }
        }
        public IQueryable<Item> Items
        {
            get { return _items.AsQueryable<Item>(); }
        }
    }
    public class OrderItems : DataService<OrderItemData>
    {
        // This method is called only once to initialize
        //service-wide policies.
        public static void InitializeService(IDataServiceConfiguration
                                             config)
        {
            config.SetEntitySetAccessRule("Orders", EntitySetRights.All);
            config.SetEntitySetAccessRule("Items", EntitySetRights.All);
        }
    }
}

另请参见

任务

如何：使用 LINQ to SQL 数据源创建数据服务（WCF 数据服务）
如何：使用 ADO.NET 实体框架数据源创建数据服务（WCF 数据服务）

概念

数据服务提供程序（WCF 数据服务）