如何：实现自定义数据类接口（实体框架）
当您将自定义数据类用于 实体数据模型 (EDM) 时，这些类必须实现以下自定义数据类接口：
IEntityWithChangeTracker。启用更改跟踪。
IEntityWithKey。可选。公开实体键。
IEntityWithRelationships。对于具有关联的实体，这是必需的。
有关更多信息，请参见实现自定义数据类接口（实体框架）。还必须应用 EDM 属性 (Attribute)，这些属性将自定义类和属性 (Property) 映射到在概念架构定义语言 (CSDL) 文件中定义的实体。有关更多信息，请参见如何：将自定义对象映射到实体（实体框架）。
您还可以从 EntityObject 继承，而不是直接实现数据类接口。这是将自定义数据类用于 EDM 的推荐方法。有关更多信息，请参见自定义对象（实体框架） 和如何：从 EntityObject 和 ComplexObject 基类继承（实体框架）。
实现自定义数据类接口
修改每个自定义数据类的定义，以便它实现 IEntityWithChangeTracker、IEntityWithKey 和 IEntityWithRelationships 接口，如以下示例所示：
<EdmEntityTypeAttribute(NamespaceName:="Microsoft.Samples.Edm", Name:="Order")> _ Public Class Order Implements IEntityWithRelationships, IEntityWithChangeTracker, IEntityWithKey[EdmEntityTypeAttribute(NamespaceName = "Microsoft.Samples.Edm", Name = "Order")] public class Order : IEntityWithRelationships, IEntityWithChangeTracker, IEntityWithKey（可选）在每个自定义数据类中显式实现 EntityKey 属性，如以下示例所示：
Dim _entityKey As EntityKey = Nothing ' Define the EntityKey property for the class. Property EntityKey() As EntityKey Implements IEntityWithKey.EntityKey Get Return _entityKey End Get Set(ByVal value As EntityKey) ' Set the EntityKey property, if it is not set. ' Report the change if the change tracker exists. If Not _changeTracker Is Nothing Then _changeTracker.EntityMemberChanging(StructuralObject.EntityKeyPropertyName) _entityKey = value _changeTracker.EntityMemberChanged(StructuralObject.EntityKeyPropertyName) Else _entityKey = value End If End Set End PropertyEntityKey _entityKey = null; // Define the EntityKey property for the class. EntityKey IEntityWithKey.EntityKey { get { return _entityKey; } set { // Set the EntityKey property, if it is not set. // Report the change if the change tracker exists. if (_changeTracker != null) { _changeTracker.EntityMemberChanging(StructuralObject.EntityKeyPropertyName); _entityKey = value; _changeTracker.EntityMemberChanged(StructuralObject.EntityKeyPropertyName); } else { _entityKey = value; } } }在每个自定义数据类中显式实现 SetChangeTracker 方法，如以下示例所示：
Dim _changeTracker As IEntityChangeTracker = Nothing ' Specify the IEntityChangeTracker to use for tracking changes. Private Sub SetChangeTracker(ByVal changeTracker As IEntityChangeTracker) _ Implements IEntityWithChangeTracker.SetChangeTracker _changeTracker = changeTracker ' Every time the change tracker is set, we must also set all the ' complex type change trackers. If Not _extendedInfo Is Nothing Then _extendedInfo.SetComplexChangeTracker("ExtendedInfo", _changeTracker) End If End SubIEntityChangeTracker _changeTracker = null; // Specify the IEntityChangeTracker to use for tracking changes. void IEntityWithChangeTracker.SetChangeTracker(IEntityChangeTracker changeTracker) { _changeTracker = changeTracker; // Every time the change tracker is set, we must also set all the // complex type change trackers. if (_extendedInfo != null) { _extendedInfo.SetComplexChangeTracker("ExtendedInfo", _changeTracker); } }若要将数据属性中的更改报告给对象服务，此方法是必需的。
对于 IEntityWithRelationships，显式实现 RelationshipManager 属性，如以下示例所示：
Dim _relationships As RelationshipManager = Nothing ' Define a relationship manager for the class. ReadOnly Property RelationshipManager() As RelationshipManager _ Implements IEntityWithRelationships.RelationshipManager Get If _relationships Is Nothing Then _relationships = RelationshipManager.Create(Me) End If Return _relationships End Get End PropertyRelationshipManager _relationships = null; // Define a relationship manager for the class. RelationshipManager IEntityWithRelationships.RelationshipManager { get { if (null == _relationships) _relationships = RelationshipManager.Create(this); return _relationships; } }在每个数据类的可设置的标量属性中，在设置 EntityMemberChanging 属性的值之前添加对此属性的调用，并在设置 EntityMemberChanged 属性之后添加对此属性的调用。下面的示例对此进行了演示：
<EdmScalarPropertyAttribute(IsNullable:=False)> _ Public Property Status() As Byte Get Return _status End Get Set(ByVal value As Byte) If _status <> value Then ' Report the change if the change tracker exists. If Not _changeTracker Is Nothing Then _changeTracker.EntityMemberChanging("Status") _status = value _changeTracker.EntityMemberChanged("Status") Else _status = value End If End If End Set End Property[EdmScalarPropertyAttribute(IsNullable = false)] public byte Status { get { return _status; } set { if (_status != value) { // Report the change if the change tracker exists. if (_changeTracker != null) { _changeTracker.EntityMemberChanging("Status"); _status = value; _changeTracker.EntityMemberChanged("Status"); } else { _status = value; } } } }在每个数据类的可设置的复杂属性中，在设置 EntityComplexMemberChanging 属性的值之前添加对此属性的调用，并在设置 EntityComplexMemberChanged 属性之后添加对此属性的调用。
示例
本示例说明自定义数据类 Order 和 LineItem 以及复杂类型 OrderInfo。这些自定义类映射到 AdventureWorks 数据库中的 SalesOrderHeader 和 SalesOrderDetail 表。这两个实体类同时实现所有这三个自定义数据类接口。OrderInfo 复杂类型类演示了建议的更改跟踪实现。
Option Explicit On
Option Strict On
Imports System
Imports System.Data.SqlTypes
Imports System.Collections.Generic
Imports System.Text
Imports System.Data
Imports System.Data.Objects.DataClasses
Imports System.Data.Metadata.Edm
Imports Microsoft.Samples.Edm
<Assembly: EdmSchemaAttribute()>
<Assembly: EdmRelationshipAttribute("Microsoft.Samples.Edm", _
"FK_LineItem_Order_OrderId", "Order", _
RelationshipMultiplicity.One, GetType(Order), "LineItem", _
RelationshipMultiplicity.Many, GetType(LineItem))>
Namespace Microsoft.Samples.Edm
<EdmEntityTypeAttribute(NamespaceName:="Microsoft.Samples.Edm", Name:="Order")> _
Public Class Order
Implements IEntityWithRelationships, IEntityWithChangeTracker, IEntityWithKey
' Define private property variables.
Private _orderId As Integer
Private _orderDate As DateTime
Private _dueDate As DateTime
Private _shipDate As DateTime
Private _status As Byte
Private _customer As Integer
Private _subTotal As Decimal
Private _tax As Decimal
Private _freight As Decimal
Private _totalDue As Decimal
Private _extendedInfo As OrderInfo
#Region "ExplicitImplementation"
Dim _changeTracker As IEntityChangeTracker = Nothing
' Specify the IEntityChangeTracker to use for tracking changes.
Private Sub SetChangeTracker(ByVal changeTracker As IEntityChangeTracker) _
Implements IEntityWithChangeTracker.SetChangeTracker
_changeTracker = changeTracker
' Every time the change tracker is set, we must also set all the
' complex type change trackers.
If Not _extendedInfo Is Nothing Then
_extendedInfo.SetComplexChangeTracker("ExtendedInfo", _changeTracker)
End If
End Sub
Dim _entityKey As EntityKey = Nothing
' Define the EntityKey property for the class.
Property EntityKey() As EntityKey Implements IEntityWithKey.EntityKey
Get
Return _entityKey
End Get
Set(ByVal value As EntityKey)
' Set the EntityKey property, if it is not set.
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging(StructuralObject.EntityKeyPropertyName)
_entityKey = value
_changeTracker.EntityMemberChanged(StructuralObject.EntityKeyPropertyName)
Else
_entityKey = value
End If
End Set
End Property
Dim _relationships As RelationshipManager = Nothing
' Define a relationship manager for the class.
ReadOnly Property RelationshipManager() As RelationshipManager _
Implements IEntityWithRelationships.RelationshipManager
Get
If _relationships Is Nothing Then
_relationships = RelationshipManager.Create(Me)
End If
Return _relationships
End Get
End Property
#End Region
' Public properties of the Order object.
<EdmScalarPropertyAttribute(EntityKeyProperty:=True, IsNullable:=False)> _
Public Property OrderId() As Integer
Get
Return _orderId
End Get
Set(ByVal value As Integer)
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("OrderId")
_orderId = value
_changeTracker.EntityMemberChanged("OrderId")
Else
_orderId = value
End If
End Set
End Property
' Navigation property that returns a collection of line items.
<EdmRelationshipNavigationPropertyAttribute("Microsoft.Samples.Edm", "FK_LineItem_Order_OrderId", "LineItem")> _
Public ReadOnly Property LineItem() As EntityCollection(Of LineItem)
Get
Return CType(Me, IEntityWithRelationships).RelationshipManager.GetRelatedCollection(Of LineItem) _
("FK_LineItem_Order_OrderId", "LineItem")
End Get
End Property
<EdmScalarPropertyAttribute(IsNullable:=False)> _
Public Property OrderDate() As Date
Get
Return _orderDate
End Get
Set(ByVal value As DateTime)
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("OrderDate")
_orderDate = value
_changeTracker.EntityMemberChanged("OrderDate")
Else
_orderDate = value
End If
End Set
End Property
<EdmScalarPropertyAttribute(IsNullable:=False)> _
Public Property DueDate() As Date
Get
Return _dueDate
End Get
Set(ByVal value As Date)
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("DueDate")
_changeTracker.EntityMemberChanged("DueDate")
Else
_dueDate = value
End If
End Set
End Property
<EdmScalarPropertyAttribute()> _
Public Property ShipDate() As Date
Get
Return _shipDate
End Get
Set(ByVal value As Date)
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("ShipDate")
_changeTracker.EntityMemberChanged("ShipDate")
Else
_shipDate = value
End If
End Set
End Property
<EdmScalarPropertyAttribute(IsNullable:=False)> _
Public Property Status() As Byte
Get
Return _status
End Get
Set(ByVal value As Byte)
If _status <> value Then
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("Status")
_status = value
_changeTracker.EntityMemberChanged("Status")
Else
_status = value
End If
End If
End Set
End Property
<EdmScalarPropertyAttribute(IsNullable:=False)> _
Public Property Customer() As Integer
Get
Return _customer
End Get
Set(ByVal value As Integer)
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("Customer")
_customer = value
_changeTracker.EntityMemberChanged("Customer")
Else
_customer = value
End If
End Set
End Property
<EdmScalarPropertyAttribute(IsNullable:=False)> _
Public Property SubTotal() As Decimal
Get
Return _subTotal
End Get
Set(ByVal value As Decimal)
If _subTotal <> value Then
' Validate the value before setting it.
If value < 0 Then
Throw New ApplicationException(String.Format( _
My.Resources.propertyNotValidNegative, _
value.ToString, "SubTotal"))
End If
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("SubTotal")
_subTotal = value
_changeTracker.EntityMemberChanged("SubTotal")
Else
_subTotal = value
End If
' Recalculate the order total.
CalculateOrderTotal()
End If
End Set
End Property
<EdmScalarPropertyAttribute(IsNullable:=False)> _
Public Property TaxAmt() As Decimal
Get
Return _tax
End Get
Set(ByVal value As Decimal)
' Validate the value before setting it.
If value < 0 Then
Throw New ApplicationException(String.Format( _
My.Resources.propertyNotValidNegative, _
value.ToString(), "Tax"))
End If
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("TaxAmt")
_tax = value
_changeTracker.EntityMemberChanged("TaxAmt")
Else
_tax = value
End If
' Recalculate the order total.
CalculateOrderTotal()
End Set
End Property
<EdmScalarPropertyAttribute(IsNullable:=False)> _
Public Property Freight() As Decimal
Get
Return _freight
End Get
Set(ByVal value As Decimal)
If _freight <> value Then
' Validate the value before setting it.
If value < 0 Then
Throw New ApplicationException(String.Format( _
My.Resources.propertyNotValidNegative, _
value.ToString(), "Freight"))
End If
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("Freight")
_freight = value
_changeTracker.EntityMemberChanging("Freight")
Else
_freight = value
End If
' Recalculate the order total.
CalculateOrderTotal()
End If
End Set
End Property
Public ReadOnly Property TotalDue() As Decimal
Get
Return _totalDue
End Get
End Property
<EdmComplexPropertyAttribute()> _
Public Property ExtendedInfo() As OrderInfo
Get
Return _extendedInfo
End Get
Set(ByVal value As OrderInfo)
' For a complex type any changes in the complex type
' properties all get tracked together.
' The change tracker may be Nothing during object materialization.
If Not _changeTracker Is Nothing Then
' Since this is a complex property, we need to reset the change
' tracker on the complex type.
If Not _extendedInfo Is Nothing Then
' Reset the change tracker.
_extendedInfo.SetComplexChangeTracker("ExtendedInfo", Nothing)
End If
' Report the change.
_changeTracker.EntityMemberChanging("ExtendedInfo")
_extendedInfo = value
_changeTracker.EntityMemberChanging("ExtendedInfo")
Else
_extendedInfo = value
End If
' Rest the change tracker. Complex type property cannot be Nothing.
If Not _extendedInfo Is Nothing Then
_extendedInfo.SetComplexChangeTracker("ExtendedInfo", _changeTracker)
End If
End Set
End Property
Private Sub CalculateOrderTotal()
' Update the total due as a sum of the other cost properties.
_totalDue = _subTotal + _tax + _freight
End Sub
End Class
' Base class for complex types that implements change tracking.
Public MustInherit Class ComplexTypeChangeTracker
Protected _complexChangeTracker As IEntityChangeTracker = Nothing
Private _rootComplexPropertyName As String
' Gets an IEntityChangeTracker to call for properties change.
' You must do this in order to track changes.
Public Overridable Sub SetComplexChangeTracker( _
ByVal rootComplexPropertyName As String, _
ByVal complexChangeTracker As IEntityChangeTracker)
_rootComplexPropertyName = rootComplexPropertyName
_complexChangeTracker = complexChangeTracker
End Sub
' Protected method that is called before the change for change tracking
' each of the scalar properties in the complex type.
Protected Sub ReportMemberChanging(ByVal scalarPropertyName As String)
If Not _complexChangeTracker Is Nothing Then
_complexChangeTracker.EntityComplexMemberChanging( _
_rootComplexPropertyName, Me, scalarPropertyName)
End If
End Sub
' Protected method that is called after the change for change tracking
' each of the scalar properties in the complex type.
Protected Sub ReportMemberChanged(ByVal scalarPropertyName As String)
If Not _complexChangeTracker Is Nothing Then
_complexChangeTracker.EntityComplexMemberChanged( _
_rootComplexPropertyName, Me, scalarPropertyName)
End If
End Sub
End Class
<EdmComplexTypeAttribute(NamespaceName:="Microsoft.Samples.Edm", Name:="OrderInfo")> _
Partial Public Class OrderInfo
Inherits ComplexTypeChangeTracker
Private _orderNumber As String
Private _purchaseOrder As String
Private _accountNumber As String
Private _comment As String
Private _extendedInfo As OrderInfo
Public Overrides Sub SetComplexChangeTracker(ByVal rootComplexPropertyName As String, _
ByVal changeTracker As IEntityChangeTracker)
' Call SetChangeTracker on the base class to set the change tracker
' and the name of the root complex type property on the entity.
MyBase.SetComplexChangeTracker(rootComplexPropertyName, changeTracker)
End Sub
<EdmScalarPropertyAttribute(IsNullable:=False)> _
Public Property OrderNumber() As String
Get
Return _orderNumber
End Get
Set(ByVal value As String)
' Validate the value before setting it.
If value.Length > 25 Then
Throw New ApplicationException(String.Format( _
My.Resources.propertyNotValidString, _
"OrderNumber", "25"))
End If
' Report the change if the change tracker exists.
If Not _complexChangeTracker Is Nothing Then
ReportMemberChanging("OrderNumber")
_orderNumber = value
ReportMemberChanged("OrderNumber")
Else
_orderNumber = value
End If
End Set
End Property
<EdmScalarPropertyAttribute()> _
Public Property PurchaseOrder() As String
Get
Return _purchaseOrder
End Get
Set(ByVal value As String)
If (value <> Nothing) AndAlso value.Length > 25 Then
Throw New ApplicationException(String.Format( _
My.Resources.propertyNotValidString, _
"PurchaseOrder", "25"))
End If
If _purchaseOrder <> value Then
' Report the change if the change tracker exists.
If Not _complexChangeTracker Is Nothing Then
ReportMemberChanging("PurchaseOrder")
_purchaseOrder = value
ReportMemberChanged("PurchaseOrder")
Else
_purchaseOrder = value
End If
End If
End Set
End Property
<EdmScalarPropertyAttribute()> _
Public Property AccountNumber() As String
Get
Return _accountNumber
End Get
Set(ByVal value As String)
' Validate the value before setting it.
If (value <> Nothing) AndAlso value.Length > 15 Then
Throw New ApplicationException(String.Format( _
My.Resources.propertyNotValidString, _
"AccountNumber", "15"))
End If
' Report the change if the change tracker exists.
If Not _complexChangeTracker Is Nothing Then
ReportMemberChanging("AccountNumber")
_accountNumber = value
ReportMemberChanged("AccountNumber")
Else
_accountNumber = value
End If
End Set
End Property
<EdmScalarPropertyAttribute()> _
Public Property Comment() As String
Get
Return _comment
End Get
Set(ByVal value As String)
' Validate the value before setting it.
If (value <> Nothing) AndAlso value.Length > 128 Then
Throw New ApplicationException(String.Format( _
My.Resources.propertyNotValidString, _
"Comment", "128"))
End If
If _comment <> value Then
' Report the change if the change tracker exists.
If Not _complexChangeTracker Is Nothing Then
ReportMemberChanging("Comment")
_comment = value
ReportMemberChanged("Comment")
Else
_comment = value
End If
End If
End Set
End Property
End Class
<EdmEntityTypeAttribute(NamespaceName:="Microsoft.Samples.Edm", Name:="LineItem")> _
Public Class LineItem
Implements IEntityWithRelationships, IEntityWithChangeTracker, IEntityWithKey
' Define private property variables.
Dim _lineItemId As Integer
Dim _trackingNumber As String
Dim _quantity As Short
Dim _product As Integer
Dim _price As Decimal
Dim _discount As Decimal
Dim _total As Decimal
Dim _changeTracker As IEntityChangeTracker = Nothing
' Specify the IEntityChangeTracker to use for tracking changes.
Private Sub SetChangeTracker(ByVal changeTracker As IEntityChangeTracker) _
Implements IEntityWithChangeTracker.SetChangeTracker
_changeTracker = changeTracker
End Sub
Dim _entityKey As EntityKey = Nothing
' Define the EntityKey property for the class.
Property EntityKey() As EntityKey Implements IEntityWithKey.EntityKey
Get
Return _entityKey
End Get
Set(ByVal value As EntityKey)
' Set the EntityKey property, if it is not set.
' Changing an existing value will cause an exception.
If _entityKey Is Nothing Then
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging(StructuralObject.EntityKeyPropertyName)
_entityKey = value
_changeTracker.EntityMemberChanged(StructuralObject.EntityKeyPropertyName)
Else
_entityKey = value
End If
End If
End Set
End Property
Dim _relationships As RelationshipManager = Nothing
' Define a relationship manager for the class.
ReadOnly Property RelationshipManager() As RelationshipManager _
Implements IEntityWithRelationships.RelationshipManager
Get
If _relationships Is Nothing Then
_relationships = RelationshipManager.Create(Me)
End If
Return _relationships
End Get
End Property
' Defines a navigation property to the Order class.
<EdmRelationshipNavigationPropertyAttribute("Microsoft.Samples.Edm", _
"FK_LineItem_Order_OrderId", "Order")> _
Public Property Order() As Order
Get
Return CType(Me, _
IEntityWithRelationships).RelationshipManager.GetRelatedReference(Of Order) _
("FK_LineItem_Order_OrderId", "Order").Value
End Get
Set(ByVal value As Order)
CType(Me, _
IEntityWithRelationships).RelationshipManager.GetRelatedReference(Of Order) _
("FK_LineItem_Order_OrderId", "Order").Value = value
End Set
End Property
<EdmScalarPropertyAttribute(EntityKeyProperty:=True, IsNullable:=False)> _
Public Property LineItemId() As Integer
Get
Return _lineItemId
End Get
Set(ByVal value As Integer)
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("LineItemId")
_lineItemId = value
_changeTracker.EntityMemberChanged("LineItemId")
Else
_lineItemId = value
End If
End Set
End Property
<EdmScalarPropertyAttribute()> _
Public Property TrackingNumber() As String
Get
Return _trackingNumber
End Get
Set(ByVal value As String)
If _trackingNumber <> value Then
' Validate the value before setting it.
If value.Length > 25 Then
Throw New ApplicationException(String.Format( _
My.Resources.propertyNotValidString, _
"TrackingNumber", "25"))
End If
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("TrackingNumber")
_trackingNumber = value
_changeTracker.EntityMemberChanged("TrackingNumber")
Else
_trackingNumber = value
End If
End If
End Set
End Property
<EdmScalarPropertyAttribute(IsNullable:=False)> _
Public Property Quantity() As Short
Get
Return _quantity
End Get
Set(ByVal value As Short)
If _quantity <> value Then
' Validate the value before setting it.
If value < 1 Then
Throw New ApplicationException(String.Format( _
My.Resources.propertyNotValidNegative, _
value.ToString(), "Quantity"))
End If
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("Quantity")
_quantity = value
_changeTracker.EntityMemberChanged("Quantity")
Else
_quantity = value
End If
' Update the line total.
CalculateLineTotal()
End If
End Set
End Property
<EdmScalarPropertyAttribute(IsNullable:=False)> _
Public Property Product() As Integer
Get
Return _product
End Get
Set(ByVal value As Integer)
' Validate the value before setting it.
If value < 1 Then
Throw New ApplicationException(String.Format( _
My.Resources.propertyNotValidNegative, _
value.ToString(), "Product"))
End If
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("Product")
_product = value
_changeTracker.EntityMemberChanged("Product")
Else
_product = value
End If
End Set
End Property
<EdmScalarPropertyAttribute(IsNullable:=False)> _
Public Property Price() As Decimal
Get
Return _price
End Get
Set(ByVal value As Decimal)
If _price <> value Then
' Validate the value before setting it.
If value < 0 Then
Throw New ApplicationException(String.Format( _
My.Resources.propertyNotValidNegative, _
value.ToString(), "Price"))
End If
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("Price")
_price = value
_changeTracker.EntityMemberChanged("Price")
Else
_price = value
End If
' Update the line total.
CalculateLineTotal()
End If
End Set
End Property
<EdmScalarPropertyAttribute(IsNullable:=False)> _
Public Property Discount() As Decimal
Get
Return _discount
End Get
Set(ByVal value As Decimal)
' Validate the value before setting it.
If value < 0 Then
Throw New ApplicationException(String.Format( _
My.Resources.propertyNotValidNegative, _
value.ToString(), "Discount"))
End If
' Report the change if the change tracker exists.
If Not _changeTracker Is Nothing Then
_changeTracker.EntityMemberChanging("Discount")
_discount = value
_changeTracker.EntityMemberChanged("Discount")
Else
_discount = value
End If
End Set
End Property
Public ReadOnly Property Total() As Decimal
Get
Return _total
End Get
End Property
Private Sub CalculateLineTotal()
_total = (_quantity * (_price - _discount))
End Sub
End Class
End Namespace
using System;
using System.Data.SqlTypes;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.Objects.DataClasses;
using System.Data.Metadata.Edm;
using Microsoft.Samples.Edm;
//using Microsoft.Samples.Edm;
[assembly: EdmSchemaAttribute()]
[assembly: EdmRelationshipAttribute("Microsoft.Samples.Edm",
"FK_LineItem_Order_OrderId", "Order",
RelationshipMultiplicity.One, typeof(Order), "LineItem",
RelationshipMultiplicity.Many, typeof(LineItem))]
namespace Microsoft.Samples.Edm
{
[EdmEntityTypeAttribute(NamespaceName = "Microsoft.Samples.Edm", Name = "Order")]
public class Order : IEntityWithRelationships, IEntityWithChangeTracker, IEntityWithKey
{
// Define private property variables.
private int _orderId;
private DateTime _orderDate;
private DateTime _dueDate;
private DateTime _shipDate;
private byte _status;
private int _customer;
private decimal _subTotal;
private decimal _tax;
private decimal _freight;
private decimal _totalDue;
private OrderInfo _extendedInfo;
#region ExplicitImplementation
IEntityChangeTracker _changeTracker = null;
// Specify the IEntityChangeTracker to use for tracking changes.
void IEntityWithChangeTracker.SetChangeTracker(IEntityChangeTracker changeTracker)
{
_changeTracker = changeTracker;
// Every time the change tracker is set, we must also set all the
// complex type change trackers.
if (_extendedInfo != null)
{
_extendedInfo.SetComplexChangeTracker("ExtendedInfo", _changeTracker);
}
}
EntityKey _entityKey = null;
// Define the EntityKey property for the class.
EntityKey IEntityWithKey.EntityKey
{
get
{
return _entityKey;
}
set
{
// Set the EntityKey property, if it is not set.
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging(StructuralObject.EntityKeyPropertyName);
_entityKey = value;
_changeTracker.EntityMemberChanged(StructuralObject.EntityKeyPropertyName);
}
else
{
_entityKey = value;
}
}
}
RelationshipManager _relationships = null;
// Define a relationship manager for the class.
RelationshipManager IEntityWithRelationships.RelationshipManager
{
get
{
if (null == _relationships)
_relationships = RelationshipManager.Create(this);
return _relationships;
}
}
#endregion
// Public properties of the Order object.
[EdmScalarPropertyAttribute(EntityKeyProperty = true, IsNullable = false)]
public int OrderId
{
get
{
return _orderId;
}
set
{
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("OrderId");
_orderId = value;
_changeTracker.EntityMemberChanged("OrderId");
}
else
{
_orderId = value;
}
}
}
// Navigation property that returns a collection of line items.
[EdmRelationshipNavigationPropertyAttribute("Microsoft.Samples.Edm", "FK_LineItem_Order_OrderId", "LineItem")]
public System.Data.Objects.DataClasses.EntityCollection<LineItem> LineItem
{
get
{
return ((IEntityWithRelationships)(this)).RelationshipManager.
GetRelatedCollection<LineItem>("FK_LineItem_Order_OrderId", "LineItem");
}
}
[EdmScalarPropertyAttribute(IsNullable = false)]
public DateTime OrderDate
{
get
{
return _orderDate;
}
set
{
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("OrderDate");
_orderDate = value;
_changeTracker.EntityMemberChanged("OrderDate");
}
else
{
_orderDate = value;
}
}
}
[EdmScalarPropertyAttribute(IsNullable = false)]
public DateTime DueDate
{
get
{
return _dueDate;
}
set
{
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("DueDate");
_dueDate = value;
_changeTracker.EntityMemberChanged("DueDate");
}
else
{
_dueDate = value;
}
}
}
[EdmScalarPropertyAttribute()]
public DateTime ShipDate
{
get
{
return _shipDate;
}
set
{
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("ShipDate");
_shipDate = value;
_changeTracker.EntityMemberChanged("ShipDate");
}
else
{
_shipDate = value;
}
}
}
[EdmScalarPropertyAttribute(IsNullable = false)]
public byte Status
{
get
{
return _status;
}
set
{
if (_status != value)
{
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("Status");
_status = value;
_changeTracker.EntityMemberChanged("Status");
}
else
{
_status = value;
}
}
}
}
[EdmScalarPropertyAttribute(IsNullable = false)]
public int Customer
{
get
{
return _customer;
}
set
{
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("Customer");
_customer = value;
_changeTracker.EntityMemberChanged("Customer");
}
else
{
_customer = value;
}
}
}
[EdmScalarPropertyAttribute(IsNullable = false)]
public decimal SubTotal
{
get
{
return _subTotal;
}
set
{
if (_subTotal != value)
{
// Validate the value before setting it.
if (value < 0)
{
throw new ApplicationException(string.Format(
Properties.Resources.propertyNotValidNegative,
new string[2] { value.ToString(), "SubTotal" }));
}
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("SubTotal");
_subTotal = value;
_changeTracker.EntityMemberChanged("SubTotal");
}
else
{
_subTotal = value;
}
// Recalculate the order total.
CalculateOrderTotal();
}
}
}
[EdmScalarPropertyAttribute(IsNullable = false)]
public decimal TaxAmt
{
get
{
return _tax;
}
set
{
// Validate the value before setting it.
if (value < 0)
{
throw new ApplicationException(string.Format(
Properties.Resources.propertyNotValidNegative,
new string[2] { value.ToString(), "Tax" }));
}
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("TaxAmt");
_tax = value;
_changeTracker.EntityMemberChanged("TaxAmt");
}
else
{
_tax = value;
}
// Recalculate the order total.
CalculateOrderTotal();
}
}
[EdmScalarPropertyAttribute(IsNullable = false)]
public decimal Freight
{
get
{
return _freight;
}
set
{
if (_freight != value)
{
// Validate the value before setting it.
if (value < 0)
{
throw new ApplicationException(string.Format(
Properties.Resources.propertyNotValidNegative,
new string[2] { value.ToString(), "Freight" }));
}
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("Freight");
_freight = value;
_changeTracker.EntityMemberChanging("Freight");
}
else
{
_freight = value;
}
// Recalculate the order total.
CalculateOrderTotal();
}
}
}
public decimal TotalDue
{
get
{
return _totalDue;
}
}
[EdmComplexPropertyAttribute()]
public OrderInfo ExtendedInfo
{
get
{
return _extendedInfo;
}
set
{
// For a complex type any changes in the complex type
// properties all get tracked together.
// The change tracker may be null during object materialization.
if (_changeTracker != null)
{
// Since this is a complex property, we need to reset the change
// tracker on the complex type.
if (_extendedInfo != null)
{
// Reset the change tracker.
_extendedInfo.SetComplexChangeTracker("ExtendedInfo", null);
}
// Report the change.
_changeTracker.EntityMemberChanging("ExtendedInfo");
_extendedInfo = value;
_changeTracker.EntityMemberChanged("ExtendedInfo");
}
else
{
_extendedInfo = value;
}
// Reset the change tracker. Complex type property cannot be null.
if (_extendedInfo != null)
{
_extendedInfo.SetComplexChangeTracker("ExtendedInfo", _changeTracker);
}
}
}
private void CalculateOrderTotal()
{
// Update the total due as a sum of the other cost properties.
_totalDue = _subTotal + _tax + _freight;
}
}
// Base class for complex types that implements change tracking.
public abstract class ComplexTypeChangeTracker
{
protected IEntityChangeTracker _complexChangeTracker = null;
private string _rootComplexPropertyName;
// Gets an IEntityChangeTracker to call for properties change.
// You must do this in order to track changes.
virtual public void SetComplexChangeTracker(string rootComplexPropertyName, IEntityChangeTracker complexChangeTracker)
{
_rootComplexPropertyName = rootComplexPropertyName;
_complexChangeTracker = complexChangeTracker;
}
// Protected method that is called before the change for change tracking
// each of the scalar properties in the complex type.
protected void ReportMemberChanging(string scalarPropertyName)
{
if (null != _complexChangeTracker)
{
_complexChangeTracker.EntityComplexMemberChanging(_rootComplexPropertyName,
this, scalarPropertyName);
}
}
// Protected method that is called after the change for change tracking
// each of the scalar properties in the complex type.
protected void ReportMemberChanged(string scalarPropertyName)
{
if (null != _complexChangeTracker)
{
_complexChangeTracker.EntityComplexMemberChanged(_rootComplexPropertyName,
this, scalarPropertyName);
}
}
}
[EdmComplexTypeAttribute(NamespaceName = "Microsoft.Samples.Edm", Name = "OrderInfo")]
public partial class OrderInfo : ComplexTypeChangeTracker
{
private string _orderNumber;
private string _purchaseOrder;
private string _accountNumber;
private string _comment;
override public void SetComplexChangeTracker(string rootComplexPropertyName, IEntityChangeTracker changeTracker)
{
// Call SetChangeTracker on the base class to set the change tracker
// and the name of the root complex type property on the entity.
base.SetComplexChangeTracker(rootComplexPropertyName, changeTracker);
}
[EdmScalarPropertyAttribute(IsNullable = false)]
public string OrderNumber
{
get
{
return _orderNumber;
}
set
{
// Validate the value before setting it.
if (value.Length > 25)
{
throw new ApplicationException(string.Format(
Properties.Resources.propertyNotValidString,
new string[3] { value, "OrderNumber", "25" }));
}
// Report the change if the change tracker exists.
if (_complexChangeTracker != null)
{
ReportMemberChanging("OrderNumber");
_orderNumber = value;
ReportMemberChanged("OrderNumber");
}
else
{
_orderNumber = value;
}
}
}
[EdmScalarPropertyAttribute()]
public string PurchaseOrder
{
get
{
return _purchaseOrder;
}
set
{
// Validate the value before setting it.
if ((value != null) && value.Length > 25)
{
throw new ApplicationException(string.Format(
Properties.Resources.propertyNotValidString,
new string[3] { value, "PurchaseOrder", "25" }));
}
if (_purchaseOrder != value)
{
// Report the change if the change tracker exists.
if (_complexChangeTracker != null)
{
ReportMemberChanging("PurchaseOrder");
_purchaseOrder = value;
ReportMemberChanged("PurchaseOrder");
}
else
{
_purchaseOrder = value;
}
}
}
}
[EdmScalarPropertyAttribute()]
public string AccountNumber
{
get
{
return _accountNumber;
}
set
{
// Validate the value before setting it.
if ((value != null) && value.Length > 15)
{
throw new ApplicationException(string.Format(
Properties.Resources.propertyNotValidString,
new string[3] { value, "AccountNumber", "15" }));
}
if (_purchaseOrder != value)
{
// Report the change if the change tracker exists.
if (_complexChangeTracker != null)
{
ReportMemberChanging("AccountNumber");
_accountNumber = value;
ReportMemberChanged("AccountNumber");
}
else
{
_accountNumber = value;
}
}
}
}
[EdmScalarPropertyAttribute()]
public string Comment
{
get
{
return _comment;
}
set
{
// Validate the value before setting it.
if ((value != null) && value.Length > 128)
{
throw new ApplicationException(string.Format(
Properties.Resources.propertyNotValidString,
new string[3] { value, "Comment", "128" }));
}
if (_comment != value)
{
// Report the change if the change tracker exists.
if (_complexChangeTracker != null)
{
ReportMemberChanging("Comment");
_comment = value;
ReportMemberChanged("Comment");
}
else
{
_comment = value;
}
}
}
}
}
[EdmEntityTypeAttribute(NamespaceName = "Microsoft.Samples.Edm",
Name = "LineItem")]
public class LineItem : IEntityWithRelationships,
IEntityWithChangeTracker, IEntityWithKey
{
// Define private property variables.
int _lineItemId;
string _trackingNumber;
short _quantity;
int _product;
decimal _price;
decimal _discount;
decimal _total;
IEntityChangeTracker _changeTracker = null;
// Specify the IEntityChangeTracker to use for tracking changes.
void IEntityWithChangeTracker.SetChangeTracker(IEntityChangeTracker changeTracker)
{
_changeTracker = changeTracker;
}
EntityKey _entityKey = null;
// Define the EntityKey property for the class.
EntityKey IEntityWithKey.EntityKey
{
get
{
return _entityKey;
}
set
{
// Set the EntityKey property, if it is not set.
// Changing an existing value will cause an exception.
if (_entityKey == null)
{
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging(StructuralObject.EntityKeyPropertyName);
_entityKey = value;
_changeTracker.EntityMemberChanged(StructuralObject.EntityKeyPropertyName);
}
else
{
_entityKey = value;
}
}
}
}
RelationshipManager _relationships = null;
// Define a relationship manager for the class.
RelationshipManager IEntityWithRelationships.RelationshipManager
{
get
{
if (null == _relationships)
_relationships = RelationshipManager.Create(this);
return _relationships;
}
}
// Defines a navigation property to the Order class.
[EdmRelationshipNavigationPropertyAttribute("Microsoft.Samples.Edm", "FK_LineItem_Order_OrderId", "Order")]
public Order Order
{
get
{
return ((IEntityWithRelationships)(this)).RelationshipManager.
GetRelatedReference<Order>("FK_LineItem_Order_OrderId", "Order").Value;
}
set
{
((IEntityWithRelationships)(this)).RelationshipManager.
GetRelatedReference<Order>("FK_LineItem_Order_OrderId", "Order").Value = value;
}
}
[EdmScalarPropertyAttribute(EntityKeyProperty = true, IsNullable = false)]
public int LineItemId
{
get
{
return _lineItemId;
}
set
{
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("LineItemId");
_lineItemId = value;
_changeTracker.EntityMemberChanged("LineItemId");
}
else
{
_lineItemId = value;
}
}
}
[EdmScalarPropertyAttribute()]
public string TrackingNumber
{
get
{
return _trackingNumber;
}
set
{
if (_trackingNumber != value)
{
// Validate the value before setting it.
if (value.Length > 25)
{
throw new ApplicationException(string.Format(
Properties.Resources.propertyNotValidString,
new string[3] {value,"TrackingNumber", "25"}));
}
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("TrackingNumber");
_trackingNumber = value;
_changeTracker.EntityMemberChanged("TrackingNumber");
}
else
{
_trackingNumber = value;
}
}
}
}
[EdmScalarPropertyAttribute(IsNullable = false)]
public short Quantity
{
get
{
return _quantity;
}
set
{
if (_quantity != value)
{
// Validate the value before setting it.
if (value < 1)
{
throw new ApplicationException(string.Format(
Properties.Resources.propertyNotValidNegative,
new string[2] { value.ToString(), "Quantity" }));
}
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("Quantity");
_quantity = value;
_changeTracker.EntityMemberChanged("Quantity");
}
else
{
_quantity = value;
}
// Update the line total.
CalculateLineTotal();
}
}
}
[EdmScalarPropertyAttribute(IsNullable = false)]
public int Product
{
get
{
return _product;
}
set
{
// Validate the value before setting it.
if (value < 1)
{
throw new ApplicationException(string.Format(
Properties.Resources.propertyNotValidNegative,
new string[2] { value.ToString(), "Product" }));
}
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("Product");
_product = value;
_changeTracker.EntityMemberChanged("Product");
}
else
{
_product = value;
}
}
}
[EdmScalarPropertyAttribute(IsNullable = false)]
public decimal Price
{
get
{
return _price;
}
set
{
if (_price != value)
{
// Validate the value before setting it.
if (value < 0)
{
throw new ApplicationException(string.Format(
Properties.Resources.propertyNotValidNegative,
new string[2] { value.ToString(), "Price" }));
}
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("Price");
_price = value;
_changeTracker.EntityMemberChanged("Price");
}
else
{
_price = value;
}
// Update the line total.
CalculateLineTotal();
}
}
}
[EdmScalarPropertyAttribute(IsNullable = false)]
public decimal Discount
{
get
{
return _discount;
}
set
{
// Validate the value before setting it.
if (value < 0)
{
throw new ApplicationException(string.Format(
Properties.Resources.propertyNotValidNegative,
new string[2] { value.ToString(), "Discount" }));
}
// Report the change if the change tracker exists.
if (_changeTracker != null)
{
_changeTracker.EntityMemberChanging("Discount");
_discount = value;
_changeTracker.EntityMemberChanged("Discount");
}
else
{
_discount = value;
}
}
}
public decimal Total
{
get
{
return _total;
}
}
private void CalculateLineTotal()
{
_total = (_quantity * (_price - _discount));
}
}
}