OnSerializingAttribute OnSerializingAttribute OnSerializingAttribute OnSerializingAttribute Class

Definición

Cuando se aplica a un método, especifica que el método está durante la serialización de un objeto de un gráfico de objetos.When applied to a method, specifies that the method is during serialization of an object in an object graph. El orden de serialización en relación con otros objetos del gráfico no es determinístico.The order of serialization relative to other objects in the graph is non-deterministic.

public ref class OnSerializingAttribute sealed : Attribute
[System.AttributeUsage(System.AttributeTargets.Method, Inherited=false)]
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class OnSerializingAttribute : Attribute
type OnSerializingAttribute = class
    inherit Attribute
Public NotInheritable Class OnSerializingAttribute
Inherits Attribute
Herencia
OnSerializingAttributeOnSerializingAttributeOnSerializingAttributeOnSerializingAttribute
Atributos

Ejemplos

El ejemplo siguiente se aplica el OnDeserializedAttribute, OnSerializingAttribute, OnSerializedAttribute, y OnDeserializingAttribute atributos a métodos en una clase.The following example applies the OnDeserializedAttribute, OnSerializingAttribute, OnSerializedAttribute, and OnDeserializingAttribute attributes to methods in a class.

using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;

public class Test
{
    public static void Main()
    {
        // Create a new TestSimpleObject object.
        TestSimpleObject obj = new TestSimpleObject();

        Console.WriteLine("\n Before serialization the object contains: ");
        obj.Print();

        // Open a file and serialize the object into binary format.
        Stream stream = File.Open("DataFile.dat", FileMode.Create);
        BinaryFormatter formatter = new BinaryFormatter();

        try
        {
            formatter.Serialize(stream, obj);

            // Print the object again to see the effect of the 
            //OnSerializedAttribute.
            Console.WriteLine("\n After serialization the object contains: ");
            obj.Print();

            // Set the original variable to null.
            obj = null;
            stream.Close();

            // Open the file "DataFile.dat" and deserialize the object from it.
            stream = File.Open("DataFile.dat", FileMode.Open);

            // Deserialize the object from the data file.
            obj = (TestSimpleObject)formatter.Deserialize(stream);

            Console.WriteLine("\n After deserialization the object contains: ");
            obj.Print();
            Console.ReadLine();
        }
        catch (SerializationException se)
        {
            Console.WriteLine("Failed to serialize. Reason: " + se.Message);
            throw;
        }
        catch (Exception exc)
        {
            Console.WriteLine("An exception occurred. Reason: " + exc.Message);
            throw;
        }
        finally
        {
            stream.Close();
            obj = null;
            formatter = null;
        }

    }
}


// This is the object that will be serialized and deserialized.
[Serializable()]
public class TestSimpleObject
{
    // This member is serialized and deserialized with no change.
    public int member1;

    // The value of this field is set and reset during and 
    // after serialization.
    private string member2;

    // This field is not serialized. The OnDeserializedAttribute 
    // is used to set the member value after serialization.
    [NonSerialized()]
    public string member3;

    // This field is set to null, but populated after deserialization.
    private string member4;

    // Constructor for the class.
    public TestSimpleObject()
    {
        member1 = 11;
        member2 = "Hello World!";
        member3 = "This is a nonserialized value";
        member4 = null;
    }

    public void Print()
    {
        Console.WriteLine("member1 = '{0}'", member1);
        Console.WriteLine("member2 = '{0}'", member2);
        Console.WriteLine("member3 = '{0}'", member3);
        Console.WriteLine("member4 = '{0}'", member4);
    }

    [OnSerializing()]
    internal void OnSerializingMethod(StreamingContext context)
    {
        member2 = "This value went into the data file during serialization.";
    }

    [OnSerialized()]
    internal void OnSerializedMethod(StreamingContext context)
    {
        member2 = "This value was reset after serialization.";
    }

    [OnDeserializing()]
    internal void OnDeserializingMethod(StreamingContext context)
    {
        member3 = "This value was set during deserialization";
    }

    [OnDeserialized()]
    internal void OnDeserializedMethod(StreamingContext context)
    {
        member4 = "This value was set after deserialization.";
    }
}

// Output:
//  Before serialization the object contains: 
// member1 = '11'
// member2 = 'Hello World!'
// member3 = 'This is a nonserialized value'
// member4 = ''
//
//  After serialization the object contains: 
// member1 = '11'
// member2 = 'This value was reset after serialization.'
// member3 = 'This is a nonserialized value'
// member4 = ''
//
//  After deserialization the object contains: 
// member1 = '11'
// member2 = 'This value went into the data file during serialization.'
// member3 = 'This value was set during deserialization'
// member4 = 'This value was set after deserialization.'
Imports System
Imports System.IO
Imports System.Runtime.Serialization
Imports System.Runtime.Serialization.Formatters.Binary

Public Class Test
    Public Shared Sub Main()
        ' Create a new TestSimpleObject object.
        Dim obj As New TestSimpleObject()

        Console.WriteLine(vbLf + " Before serialization the object contains: ")
        obj.Print()

        ' Open a file and serialize the object into binary format.
        Dim stream As Stream = File.Open("DataFile.dat", FileMode.Create)
        Dim formatter As New BinaryFormatter()

        Try
            formatter.Serialize(stream, obj)

            ' Print the object again to see the effect of the 
            'OnSerializedAttribute.
            Console.WriteLine(vbLf + " After serialization the object contains: ")
            obj.Print()

            ' Set the original variable to null.
            obj = Nothing
            stream.Close()

            ' Open the file "DataFile.dat" and deserialize the object from it.
            stream = File.Open("DataFile.dat", FileMode.Open)

            ' Deserialize the object from the data file.
            obj = CType(formatter.Deserialize(stream), TestSimpleObject)

            Console.WriteLine(vbLf + " After deserialization the object contains: ")
            obj.Print()
            Console.ReadLine()
        Catch se As SerializationException
            Console.WriteLine("Failed to serialize. Reason: " + se.Message)
            Throw
        Catch exc As Exception
            Console.WriteLine("An exception occurred. Reason: " + exc.Message)
            Throw
        Finally
            stream.Close()
            obj = Nothing
            formatter = Nothing
        End Try
    End Sub
End Class


' This is the object that will be serialized and deserialized.
<Serializable()> _
Public Class TestSimpleObject
    ' This member is serialized and deserialized with no change.
    Public member1 As Integer

    ' The value of this field is set and reset during and 
    ' after serialization.
    Private member2 As String

    ' This field is not serialized. The OnDeserializedAttribute 
    ' is used to set the member value after serialization.
    <NonSerialized()> _
    Public member3 As String

    ' This field is set to null, but populated after deserialization.
    Private member4 As String

    ' Constructor for the class.
    Public Sub New()
        member1 = 11
        member2 = "Hello World!"
        member3 = "This is a nonserialized value"
        member4 = Nothing
    End Sub

    Public Sub Print()
        Console.WriteLine("member1 = '{0}'", member1)
        Console.WriteLine("member2 = '{0}'", member2)
        Console.WriteLine("member3 = '{0}'", member3)
        Console.WriteLine("member4 = '{0}'", member4)
    End Sub

    <OnSerializing()> _
    Friend Sub OnSerializingMethod(ByVal context As StreamingContext)
        member2 = "This value went into the data file during serialization."
    End Sub

    <OnSerialized()> _
    Friend Sub OnSerializedMethod(ByVal context As StreamingContext)
        member2 = "This value was reset after serialization."
    End Sub

    <OnDeserializing()> _
    Friend Sub OnDeserializingMethod(ByVal context As StreamingContext)
        member3 = "This value was set during deserialization"
    End Sub

    <OnDeserialized()> _
    Friend Sub OnDeserializedMethod(ByVal context As StreamingContext)
        member4 = "This value was set after deserialization."
    End Sub
End Class

' Output:
'  Before serialization the object contains: 
' member1 = '11'
' member2 = 'Hello World!'
' member3 = 'This is a nonserialized value'
' member4 = ''
'
'  After serialization the object contains: 
' member1 = '11'
' member2 = 'This value was reset after serialization.'
' member3 = 'This is a nonserialized value'
' member4 = ''
'
'  After deserialization the object contains: 
' member1 = '11'
' member2 = 'This value went into the data file during serialization.'
' member3 = 'This value was set during deserialization'
' member4 = 'This value was set after deserialization.'

Comentarios

Use el OnSerializingAttribute para manipular el objeto antes de que se produce la serialización.Use the OnSerializingAttribute to manipulate the object before serialization occurs.

Para usar el OnSerializingAttribute, el método debe contener un StreamingContext parámetro.To use the OnSerializingAttribute, the method must contain a StreamingContext parameter. El atributo marca el método al que llamar por la infraestructura de serialización y el StreamingContext proporciona datos adicionales sobre el tipo de serialización que se lleva a cabo.The attribute marks the method to be called by the serialization infrastructure and the StreamingContext provides additional data about the type of serialization taking place. En el código siguiente se muestra el uso de:The usage is shown in the following code:

[OnSerializing]
private void SetValuesOnSerializing(StreamingContext context)
{
    // Code not shown.
}
<OnSerializing()> _
Private Sub SetValuesOnSerializing(ByVal context As StreamingContext)
    ' Code not shown.
End Sub

Nota

En el código, se puede usar la palabra OnSerializing en lugar de OnSerializingAttribute, que resulta más largo.In your code, you can use the word OnSerializing instead of the longer OnSerializingAttribute.

Cuando se usa la serialización binaria, el proceso de serialización binaria omite la llamada a la onSerializing método cuando los objetos serializados son iguales.When using binary serialization, the binary serialization process omits the call to the onSerializing method when the serialized objects are equal. Por lo tanto, cuando se usa el BinaryFormatter tipo con el equals método (o Object.GetHashCode), por ejemplo, el resultado puede ser un comportamiento indefinido.Therefore, when using the BinaryFormatter type with the equals method (or Object.GetHashCode) for example, the result may be undefined behavior.

Constructores

OnSerializingAttribute() OnSerializingAttribute() OnSerializingAttribute() OnSerializingAttribute()

Inicializa una nueva instancia de la clase OnSerializingAttribute.Initializes a new instance of the OnSerializingAttribute class.

Métodos

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Devuelve un valor que indica si esta instancia es igual que un objeto especificado.Returns a value that indicates whether this instance is equal to a specified object.

(Inherited from Attribute)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Devuelve el código hash de esta instancia.Returns the hash code for this instance.

(Inherited from Attribute)
GetType() GetType() GetType() GetType()

Obtiene el Type de la instancia actual.Gets the Type of the current instance.

(Inherited from Object)
IsDefaultAttribute() IsDefaultAttribute() IsDefaultAttribute() IsDefaultAttribute()

Si se reemplaza en una clase derivada, indica si el valor de esta instancia es el valor predeterminado de la clase derivada.When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.

(Inherited from Attribute)
Match(Object) Match(Object) Match(Object) Match(Object)

Cuando se invalida en una clase derivada, devuelve un valor que indica si esta instancia es igual a un objeto especificado.When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.

(Inherited from Attribute)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Crea una copia superficial del objeto Object actual.Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Devuelve una cadena que representa el objeto actual.Returns a string that represents the current object.

(Inherited from Object)

Implementaciones de interfaz explícitas

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr) _Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr) _Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr) _Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Asigna un conjunto de nombres a un conjunto correspondiente de identificadores de envío.Maps a set of names to a corresponding set of dispatch identifiers.

(Inherited from Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) _Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) _Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) _Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Obtiene la información de tipos de un objeto, que puede utilizarse para obtener la información de tipos de una interfaz.Retrieves the type information for an object, which can be used to get the type information for an interface.

(Inherited from Attribute)
_Attribute.GetTypeInfoCount(UInt32) _Attribute.GetTypeInfoCount(UInt32) _Attribute.GetTypeInfoCount(UInt32) _Attribute.GetTypeInfoCount(UInt32)

Recupera el número de interfaces de información de tipo que proporciona un objeto (0 ó 1).Retrieves the number of type information interfaces that an object provides (either 0 or 1).

(Inherited from Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) _Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) _Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) _Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Proporciona acceso a las propiedades y los métodos expuestos por un objeto.Provides access to properties and methods exposed by an object.

(Inherited from Attribute)

Propiedades

TypeId TypeId TypeId TypeId

Cuando se implementa en una clase derivada, obtiene un identificador único para este Attribute.When implemented in a derived class, gets a unique identifier for this Attribute.

(Inherited from Attribute)

Se aplica a

Consulte también: