EntityPropertyMappingAttribute 类

参考

定义

命名空间:: System.Data.Services.Common

程序集:: System.Data.Services.Client.dll

重要

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指定实体类型的属性与 WCF Data Services 返回的源中某项的元素之间自定义映射的特性。

public ref class EntityPropertyMappingAttribute sealed : Attribute

[System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=true, Inherited=true)]
public sealed class EntityPropertyMappingAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=true, Inherited=true)>]
type EntityPropertyMappingAttribute = class
    inherit Attribute

Public NotInheritable Class EntityPropertyMappingAttribute
Inherits Attribute

继承: Object

Attribute
EntityPropertyMappingAttribute

属性: AttributeUsageAttribute

示例

在以下示例中，类型的 Order 两个属性都映射到现有源元素。 Product 类型的 Item 属性映射到单独的命名空间中的自定义源特性。

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

namespace CustomDataService
{
    [EntityPropertyMappingAttribute("Customer",
        SyndicationItemProperty.AuthorName,
        SyndicationTextContentKind.Plaintext, true)]
    [EntityPropertyMapping("OrderId",
        SyndicationItemProperty.Title,
        SyndicationTextContentKind.Plaintext, false)]
    [DataServiceKeyAttribute("OrderId")]
    public class Order
    {
        public int OrderId { get; set; }
        public string Customer { get; set; }
        public IList<Item> Items { get; set; }
    }
    [EntityPropertyMappingAttribute("Product", "productname",
     "orders", "http://schema.examples.microsoft.com/dataservices", true)]
    [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(); }
        }
        public IQueryable<Item> Items
        {
            get { return _items.AsQueryable(); }
        }
    }

    public class OrderItems : DataService<OrderItemData>
    {
        // This method is called only once to initialize
        //service-wide policies.
        public static void InitializeService(DataServiceConfiguration
                                             config)
        {
            config.SetEntitySetAccessRule("Orders",
               EntitySetRights.AllRead |
               EntitySetRights.AllWrite);
            config.SetEntitySetAccessRule("Items",
                EntitySetRights.AllRead |
                EntitySetRights.AllWrite);
            config.DataServiceBehavior.MaxProtocolVersion =
                DataServiceProtocolVersion.V2;
        }
    }
}

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

Namespace CustomDataService
    <EntityPropertyMappingAttribute("Customer", _
        SyndicationItemProperty.AuthorName, _
        SyndicationTextContentKind.Plaintext, True)> _
    <EntityPropertyMapping("OrderId", _
        SyndicationItemProperty.Title, _
        SyndicationTextContentKind.Plaintext, False)> _
    <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.AllRead _
                                          Or EntitySetRights.AllWrite)
            config.SetEntitySetAccessRule("Items", _
                                          EntitySetRights.AllRead _
                                          Or EntitySetRights.AllWrite)
            config.DataServiceBehavior.MaxProtocolVersion =
                DataServiceProtocolVersion.V2
        End Sub
    End Class
End Namespace

上面的示例为 URI http://myservice/OrderItems.svc/Orders(0)?$expand=Items 返回以下结果。

<entry xml:base="http://localhost:12345/OrderItems.svc/" 
       xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" 
       xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" 
       xmlns="http://www.w3.org/2005/Atom">
  <id>http://localhost:12345/OrderItems.svc/Orders(0)</id>
  <title type="text">0</title>
  <updated>2009-07-25T21:12:30Z</updated>
  <author>
    <name>Peter Franken</name>
  </author>
  <link rel="edit" title="Order" href="Orders(0)" />
  <link rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/Items" 
        type="application/atom+xml;type=feed" title="Items" href="Orders(0)/Items">
    <m:inline>
      <feed>
        <title type="text">Items</title>
        <id>http://localhost:12345/OrderItems.svc/Orders(0)/Items</id>
        <updated>2009-07-25T21:12:30Z</updated>
        <link rel="self" title="Items" href="Orders(0)/Items" />
        <entry>
          <id>http://localhost:12345/OrderItems.svc/Items('Chai')</id>
          <title type="text" />
          <updated>2009-07-25T21:12:30Z</updated>
          <author>
            <name />
          </author>
          <link rel="edit" title="Item" href="Items('Chai')" />
          <category term="CustomDataService.Item" 
                    scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" />
          <content type="application/xml">
            <m:properties>
              <d:Product>Chai</d:Product>
              <d:Quantity m:type="Edm.Int32">10</d:Quantity>
            </m:properties>
          </content>
          <orders:productname 
            xmlns:orders="http://schema.examples.microsoft.com/dataservices">Chai</orders:productname>
        </entry>
        <entry>
          <id>http://localhost:12345/OrderItems.svc/Items('Chang')</id>
          <title type="text" />
          <updated>2009-07-25T21:12:30Z</updated>
          <author>
            <name />
          </author>
          <link rel="edit" title="Item" href="Items('Chang')" />
          <category term="CustomDataService.Item" 
                    scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" />
          <content type="application/xml">
            <m:properties>
              <d:Product>Chang</d:Product>
              <d:Quantity m:type="Edm.Int32">25</d:Quantity>
            </m:properties>
          </content>
          <orders:productname 
            xmlns:orders="http://schema.examples.microsoft.com/dataservices">Chang</orders:productname>
        </entry>
      </feed>
    </m:inline>
  </link>
  <category term="CustomDataService.Order" 
            scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" />
  <content type="application/xml">
    <m:properties>
      <d:Customer>Peter Franken</d:Customer>
    </m:properties>
  </content>
</entry>

注解

EntityPropertyMappingAttribute用于在反射提供程序的数据模型中定义自定义源映射。当用于生成类的元数据指示在数据模型中定义了自定义源映射时，此属性也会应用于生成的客户端数据服务类。此信息是确保客户端可以创建和使用支持自定义源的消息所必需的。有关详细信息，请参阅源自定义。

构造函数

EntityPropertyMappingAttribute(String, String, String, String, Boolean)	创建 EntityPropertyMappingAttribute 的实例以将属性映射到自定义源元素。
EntityPropertyMappingAttribute(String, SyndicationItemProperty, SyndicationTextContentKind, Boolean)	创建 EntityPropertyMappingAttribute 的新实例。

属性

KeepInContent	获取一个布尔值，该值指示是否应在源的内容部分和映射位置都出现同一属性值。
SourcePath	获取将映射到源的指定元素的联合项的属性名称。
TargetNamespacePrefix	获取一个字符串值，该值与 TargetNamespaceUri 一起指定 TargetPath 元素所在的命名空间。
TargetNamespaceUri	获取一个字符串值，该值指定由 TargetPath 属性指定的元素的命名空间 URI。
TargetPath	获取属性将映射到的源中的自定义目标的名称。
TargetSyndicationItem	获取 SyndicationItem 类的属性。
TargetTextContentKind	获取由 EntityPropertyMappingAttribute 映射的属性的内容类型。
TypeId	在派生类中实现时，获取此 Attribute 的唯一标识符。 (继承自 Attribute)

方法

Equals(Object)	返回一个值，该值指示此实例是否与指定的对象相等。 (继承自 Attribute)
GetHashCode()	返回此实例的哈希代码。 (继承自 Attribute)
GetType()	获取当前实例的 Type。 (继承自 Object)
IsDefaultAttribute()	在派生类中重写时，指示此实例的值是否是派生类的默认值。 (继承自 Attribute)
Match(Object)	当在派生类中重写时，返回一个指示此实例是否等于指定对象的值。 (继承自 Attribute)
MemberwiseClone()	创建当前 Object 的浅表副本。 (继承自 Object)
ToString()	返回表示当前对象的字符串。 (继承自 Object)

显式接口实现

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)	将一组名称映射为对应的一组调度标识符。 (继承自 Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)	检索对象的类型信息，然后可以使用该信息获取接口的类型信息。 (继承自 Attribute)
_Attribute.GetTypeInfoCount(UInt32)	检索对象提供的类型信息接口的数量（0 或 1）。 (继承自 Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)	提供对某一对象公开的属性和方法的访问。 (继承自 Attribute)

适用于

另请参阅

如何：使用反射提供程序创建数据服务（WCF 数据服务）

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通过

EntityPropertyMappingAttribute 类

定义

示例

注解

构造函数

属性

方法

显式接口实现

适用于

另请参阅

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