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Cómo heredar de las clases base EntityObject y ComplexObject (Entity Framework)

Si se usan clases de datos personalizadas con un modelo Entity Data Model (EDM), se deben actualizar para que hereden de EntityObject y ComplexObject. También debe aplicar atributos de EDM que asignan las clases y las propiedades personalizadas a los tipos de entidad y tipos complejos definidos en el archivo del lenguaje de definición de esquemas conceptuales (CSDL). Para obtener más información, vea Cómo asignar objetos personalizados a las entidades (Entity Framework).

En lugar de heredar de EntityObject o ComplexObject, también se pueden implementar interfaces de clases de datos personalizadas. Para obtener más información, vea Implementar interfaces de clases de datos personalizadas (Entity Framework).

Para heredar de EntityObject

  1. Modifique la definición de cada clase de datos personalizada para que herede de EntityObject, como en el ejemplo siguiente:

    <EdmEntityTypeAttribute(NamespaceName:="Microsoft.Samples.Edm", Name:="Order")> _
    Public Class Order
        Inherits EntityObject
    
    [EdmEntityTypeAttribute(NamespaceName="Microsoft.Samples.Edm",Name="Order")]
    public class Order : EntityObject 
    
  2. En las propiedades escalares configurables de cada clase de datos, agregue una llamada a ReportPropertyChanging antes de establecer el valor de la propiedad, y agregue una llamada a ReportPropertyChanged una vez establecida la propiedad. Esto se muestra en el ejemplo siguiente:

    Set(ByVal value As Integer)
        ReportPropertyChanging("OrderId")
        _orderId = value
        ReportPropertyChanged("OrderId")
    End Set
    
    set
    {
        ReportPropertyChanging("OrderId");
        _orderId = value;
        ReportPropertyChanged("OrderId");
    }
    

Cómo heredar de ComplexObject

  1. Modifique la definición de cada clase de datos compleja para que herede de ComplexObject, como en el ejemplo siguiente:

    <Global.System.Data.Objects.DataClasses.EdmComplexTypeAttribute( _
        NamespaceName:="Microsoft.Samples.Edm", Name:="OrderInfo")> _
    Partial Public Class OrderInfo
        Inherits Global.System.Data.Objects.DataClasses.ComplexObject
    
    [EdmComplexTypeAttribute(NamespaceName = 
        "Microsoft.Samples.Edm", Name = "OrderInfo")]
    public partial class OrderInfo : ComplexObject
    
  2. En las propiedades escalares configurables de cada clase de datos compleja, agregue una llamada a ReportPropertyChanging antes de establecer el valor de la propiedad, y agregue una llamada a ReportPropertyChanged una vez establecida la propiedad. Esto se muestra en el ejemplo siguiente:

    ' Validate the value before setting it.
    If (value <> Nothing) AndAlso value.Length > 25 Then
        Throw New ApplicationException(String.Format( _
                  My.Resources.propertyNotValidString, _
                  "PurchaseOrder", "25"))
    End If
    If _purchaseOrder <> value Then
        ReportPropertyChanging("PurchaseOrder")
        _purchaseOrder = value
        ReportPropertyChanged("PurchaseOrder")
    End If
    
    // 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)
    {
        ReportPropertyChanging("PurchaseOrder");
        _purchaseOrder = value;
        ReportPropertyChanged("PurchaseOrder");
    }
    

Ejemplo

En este ejemplo se muestran las clases de datos personalizadas Order y LineItem, y la clase de datos compleja OrderInfo. Estas clases personalizadas se asignan a las tablas SalesOrderHeader y SalesOrderDetail de la base de datos AdventureWorks. Las clases Order y LineItem heredan de EntityObject y la clase de datos compleja OrderInfo hereda de ComplexObject.

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
        Inherits EntityObject
        ' 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

        'Default Constructor.
        Sub New()

        End Sub
        ' 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)
                ReportPropertyChanging("OrderId")
                _orderId = value
                ReportPropertyChanged("OrderId")
            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)
                ReportPropertyChanging("OrderDate")
                _orderDate = value
                ReportPropertyChanged("OrderDate")
            End Set
        End Property
        <EdmScalarPropertyAttribute(IsNullable:=False)> _
        Public Property DueDate() As Date
            Get
                Return _dueDate
            End Get
            Set(ByVal value As Date)
                ReportPropertyChanging("DueDate")
                _dueDate = value
                ReportPropertyChanged("DueDate")
            End Set
        End Property
        <EdmScalarPropertyAttribute()> _
        Public Property ShipDate() As Date
            Get
                Return _shipDate
            End Get
            Set(ByVal value As Date)
                ReportPropertyChanging("ShipDate")
                _shipDate = value
                ReportPropertyChanged("ShipDate")
            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
                    ReportPropertyChanging("Status")
                    _status = value
                    ReportPropertyChanged("Status")
                End If
            End Set
        End Property
        <EdmScalarPropertyAttribute(IsNullable:=False)> _
        Public Property Customer() As Integer
            Get
                Return _customer
            End Get
            Set(ByVal value As Integer)
                ReportPropertyChanging("Customer")
                _customer = value
                ReportPropertyChanged("Customer")
            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
                    ReportPropertyChanging("SubTotal")
                    _subTotal = value
                    ReportPropertyChanged("SubTotal")

                    ' 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
                ReportPropertyChanging("TaxAmt")
                _tax = value
                ReportPropertyChanged("TaxAmt")

                ' 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
                    ReportPropertyChanging("Freight")
                    _freight = value
                    ReportPropertyChanging("Freight")

                    ' 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)
                ReportPropertyChanging("ExtendedInfo")
                _extendedInfo = value
                ReportPropertyChanged("ExtendedInfo")
            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
    <Global.System.Data.Objects.DataClasses.EdmComplexTypeAttribute( _
        NamespaceName:="Microsoft.Samples.Edm", Name:="OrderInfo")> _
    Partial Public Class OrderInfo
        Inherits Global.System.Data.Objects.DataClasses.ComplexObject
        Private _orderNumber As String
        Private _purchaseOrder As String
        Private _accountNumber As String
        Private _comment As String
        <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
                ReportPropertyChanging("OrderNumber")
                _orderNumber = value
                ReportPropertyChanged("OrderNumber")
            End Set
        End Property
        <EdmScalarPropertyAttribute()> _
        Public Property PurchaseOrder() As String
            Get
                Return _purchaseOrder
            End Get
            Set(ByVal value As String)
                ' Validate the value before setting it.
                If (value <> Nothing) AndAlso value.Length > 25 Then
                    Throw New ApplicationException(String.Format( _
                              My.Resources.propertyNotValidString, _
                              "PurchaseOrder", "25"))
                End If
                If _purchaseOrder <> value Then
                    ReportPropertyChanging("PurchaseOrder")
                    _purchaseOrder = value
                    ReportPropertyChanged("PurchaseOrder")
                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
                ReportPropertyChanging("AccountNumber")
                _accountNumber = value
                ReportPropertyChanged("AccountNumber")
            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
                    ReportPropertyChanging("Comment")
                    _comment = value
                    ReportPropertyChanged("Comment")
                End If
            End Set
        End Property
    End Class
    <EdmEntityTypeAttribute(NamespaceName:="Microsoft.Samples.Edm", _
                            Name:="LineItem")> _
    Public Class LineItem
        Inherits EntityObject

        ' 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
        Sub New()

        End Sub
        ' 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)
                ReportPropertyChanging("LineItemId")
                _lineItemId = value
                ReportPropertyChanged("LineItemId")
            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
                    ReportPropertyChanging("TrackingNumber")
                    _trackingNumber = value
                    ReportPropertyChanged("TrackingNumber")
                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
                    ReportPropertyChanging("Quantity")
                    _quantity = value
                    ReportPropertyChanged("Quantity")

                    ' 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
                ReportPropertyChanging("Product")
                _product = value
                ReportPropertyChanged("Product")
            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
                    ReportPropertyChanging("Price")
                    _price = value
                    ReportPropertyChanged("Price")

                    ' 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
                ReportPropertyChanging("Discount")
                _discount = value
                ReportPropertyChanged("Discount")
            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;

[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 : EntityObject 
    {
        // 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;
        
        // Public properties of the Order object.
        [EdmScalarPropertyAttribute(EntityKeyProperty = true, IsNullable = false)]
        public int OrderId
        {
            get 
            {
                return _orderId;
            }
            set
            {
                ReportPropertyChanging("OrderId");
                _orderId = value;
                ReportPropertyChanged("OrderId");
            }
        }

        // 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
            {
                ReportPropertyChanging("OrderDate");
                _orderDate = value;
                ReportPropertyChanged("OrderDate");
            }
        }
        [EdmScalarPropertyAttribute(IsNullable = false)]
        public DateTime DueDate 
        {
            get 
            {
                return _dueDate;
            }
            set
            {
                ReportPropertyChanging("DueDate");
                _dueDate = value;
                ReportPropertyChanged("DueDate");
            }
        }
        [EdmScalarPropertyAttribute()]
        public DateTime ShipDate
        {
            get
            {
                return _shipDate;
            }
            set
            {
                ReportPropertyChanging("ShipDate");
                _shipDate = value;
                ReportPropertyChanged("ShipDate");

            }
        }
        [EdmScalarPropertyAttribute(IsNullable = false)]
        public byte Status
        {
            get 
            {
                return _status;
            }
            set
            {
                if (_status != value)
                {
                    ReportPropertyChanging("Status");
                    _status = value;
                    ReportPropertyChanged("Status");
                }
            }
        }
        [EdmScalarPropertyAttribute(IsNullable = false)]
        public int Customer
        {
            get
            {
                return _customer;
            }
            set
            {
                ReportPropertyChanging("Customer");
                _customer = value;
                ReportPropertyChanged("Customer");
            }
        }
        [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" }));
                    }

                    ReportPropertyChanging("SubTotal");
                    _subTotal = value;
                    ReportPropertyChanged("SubTotal");

                    // 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" }));
                }

                ReportPropertyChanging("TaxAmt");
                _tax = value;
                ReportPropertyChanged("TaxAmt");

                // 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" }));
                    }

                    ReportPropertyChanging("Freight");
                    _freight = value;
                    ReportPropertyChanging("Freight");

                    // Recalculate the order total.
                    CalculateOrderTotal();
                }
            }

        }
        public decimal TotalDue
        {
            get
            {
                return _totalDue;
            }
        }

        [EdmComplexPropertyAttribute()]
        public OrderInfo ExtendedInfo
        {
            get
            {
                return _ExtendedInfo;
            }
            set
            {
                this.ReportPropertyChanging("ExtendedInfo");
                _ExtendedInfo = value;
                this.ReportPropertyChanged("ExtendedInfo");                
            }
        }
        private void CalculateOrderTotal()
        {
            // Update the total due as a sum of the other cost properties.
            _totalDue = _subTotal + _tax + _freight;
        }
}
    [EdmComplexTypeAttribute(NamespaceName = 
        "Microsoft.Samples.Edm", Name = "OrderInfo")]
    public partial class OrderInfo : ComplexObject
    {
        private string _orderNumber;
        private string _purchaseOrder;
        private string _accountNumber;
        private string _comment;

        [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" }));
                }

                ReportPropertyChanging("OrderNumber");
                _orderNumber = value;
                ReportPropertyChanged("OrderNumber");
            }
        }
        [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)
                {
                    ReportPropertyChanging("PurchaseOrder");
                    _purchaseOrder = value;
                    ReportPropertyChanged("PurchaseOrder");
                }
            }
        }
        [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" }));
                }
                ReportPropertyChanging("AccountNumber");
                _accountNumber = value;
                ReportPropertyChanged("AccountNumber");
            }
        }
        [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)
                {
                    ReportPropertyChanging("Comment");
                    _comment = value;
                    ReportPropertyChanged("Comment");
                }
            }
        }
    }

    [EdmEntityTypeAttribute(NamespaceName = "Microsoft.Samples.Edm", Name = "LineItem")]
    public class LineItem : EntityObject  
    {
        // Define private property variables.
        int _lineItemId; 
        string _trackingNumber;
        short _quantity;
        int _product;
        decimal _price;
        decimal _discount;
        decimal _total;

        // Default constructor.
        public LineItem()
        {

        }   

        // 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
            {
                ReportPropertyChanging("LineItemId");
                _lineItemId = value;
                ReportPropertyChanged("LineItemId");
            }
        }
        [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"}));
                    }
                    ReportPropertyChanging("TrackingNumber");
                    _trackingNumber = value;
                    ReportPropertyChanged("TrackingNumber");
                }
            }
        }
        [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" }));
                    }
                    ReportPropertyChanging("Quantity");
                    _quantity = value;
                    ReportPropertyChanged("Quantity");
 
                    // 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" }));
                }
                ReportPropertyChanging("Product");
                _product = value;
                ReportPropertyChanged("Product");
            }
        }
        [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" }));
                    }

                    ReportPropertyChanging("Price");
                    _price = value;
                    ReportPropertyChanged("Price");

                    // 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" }));
                }
                ReportPropertyChanging("Discount");
                _discount = value;
                ReportPropertyChanged("Discount");
            }
        }
 
        public decimal Total
        {
            get
            {
                return _total;
            }
        }

        private void CalculateLineTotal()
        {
            _total = (_quantity * (_price - _discount)); 
        }
    }
}

Vea también

Tareas

Cómo personalizar un modelo Entity Data Model para trabajar con objetos personalizados (Entity Framework)
Cómo implementar interfaces de clases de datos personalizadas (Entity Framework)

Conceptos

Personalizar objetos (Entity Framework)

Otros recursos

Trabajar con objetos personalizados (tareas de Entity Framework)