ISerializable Interfaz

Definición

Permite que un objeto controle su propia serialización y deserialización.Allows an object to control its own serialization and deserialization.

public interface class ISerializable
[System.Runtime.InteropServices.ComVisible(true)]
public interface ISerializable
type ISerializable = interface
Public Interface ISerializable
Derivado
Atributos

Ejemplos

En el ejemplo de código siguiente se muestra el ISerializable uso de la interfaz para definir el comportamiento de serialización personalizado para una clase.The following code example demonstrates the use of the ISerializable interface to define custom serialization behavior for a class.

using namespace System;
using namespace System::IO;
using namespace System::Collections;
using namespace System::Runtime::Serialization::Formatters::Binary;
using namespace System::Runtime::Serialization;

ref class SingletonSerializationHelper;

// There should be only one instance of this type per AppDomain.

[Serializable]
public ref class Singleton sealed: public ISerializable
{
private:

   // This is the one instance of this type.
   static Singleton^ theOneObject = gcnew Singleton;

public:

   // Here are the instance fields.
   String^ someString;
   Int32 someNumber;

private:

   // Private constructor allowing this type to construct the singleton.
   Singleton()
   {
      
      // Do whatever is necessary to initialize the singleton.
      someString = "This is a String* field";
      someNumber = 123;
   }

public:

   // A method returning a reference to the singleton.
   static Singleton^ GetSingleton()
   {
      return theOneObject;
   }

   // A method called when serializing a Singleton.
   [System::Security::Permissions::SecurityPermissionAttribute
   (System::Security::Permissions::SecurityAction::LinkDemand, 
   Flags=System::Security::Permissions::SecurityPermissionFlag::SerializationFormatter)]
   virtual void GetObjectData( SerializationInfo^ info, StreamingContext context )
   {
      // Instead of serializing this Object*, we will  
      // serialize a SingletonSerializationHelp instead.
      info->SetType( SingletonSerializationHelper::typeid );

      // No other values need to be added.
   }

   // NOTE: ISerializable*'s special constructor is NOT necessary 
   // because it's never called
};

[Serializable]
private ref class SingletonSerializationHelper sealed: public IObjectReference
{
public:

   // This Object* has no fields (although it could).
   // GetRealObject is called after this Object* is deserialized
   virtual Object^ GetRealObject( StreamingContext context )
   {
      // When deserialiing this Object*, return a reference to 
      // the singleton Object* instead.
      return Singleton::GetSingleton();
   }
};

[STAThread]
int main()
{
   FileStream^ fs = gcnew FileStream( "DataFile.dat",FileMode::Create );
   try
   {
      // Construct a BinaryFormatter and use it 
      // to serialize the data to the stream.
      BinaryFormatter^ formatter = gcnew BinaryFormatter;

      // Create an array with multiple elements refering to 
      // the one Singleton Object*.
      array<Singleton^>^a1 = {Singleton::GetSingleton(),Singleton::GetSingleton()};

      // This displays S"True".
      Console::WriteLine( "Do both array elements refer to the same Object? {0}", (a1[ 0 ] == a1[ 1 ]) );

      // Serialize the array elements.
      formatter->Serialize( fs, a1 );

      // Deserialize the array elements.
      fs->Position = 0;
      array<Singleton^>^a2 = (array<Singleton^>^)formatter->Deserialize( fs );

      // This displays S"True".
      Console::WriteLine( "Do both array elements refer to the same Object? {0}", (a2[ 0 ] == a2[ 1 ]) );

      // This displays S"True".
      Console::WriteLine( "Do all  array elements refer to the same Object? {0}", (a1[ 0 ] == a2[ 0 ]) );
   }
   catch ( SerializationException^ e ) 
   {
      Console::WriteLine( "Failed to serialize. Reason: {0}", e->Message );
      throw;
   }
   finally
   {
      fs->Close();
   }

   return 0;
}
using System;
using System.Text;
using System.IO;
// Add references to Soap and Binary formatters.
using System.Runtime.Serialization.Formatters.Binary;
using System.Runtime.Serialization.Formatters.Soap ;
using System.Runtime.Serialization;


[Serializable]
public class MyItemType : ISerializable
{
    public MyItemType()
    {
        // Empty constructor required to compile.
    }

    // The value to serialize.
    private string myProperty_value;

    public string MyProperty
    {
        get { return myProperty_value; }
        set { myProperty_value = value; }
    }
        
    // Implement this method to serialize data. The method is called 
    // on serialization.
    public void GetObjectData(SerializationInfo info, StreamingContext context)
    {
        // Use the AddValue method to specify serialized values.
        info.AddValue("props", myProperty_value, typeof(string));

    }

    // The special constructor is used to deserialize values.
    public MyItemType(SerializationInfo info, StreamingContext context)
    {
        // Reset the property value using the GetValue method.
        myProperty_value = (string) info.GetValue("props", typeof(string));
    }
}

// This is a console application. 
public static class Test
{
    static void Main()
    {
        // This is the name of the file holding the data. You can use any file extension you like.
        string fileName = "dataStuff.myData";

        // Use a BinaryFormatter or SoapFormatter.
        IFormatter formatter = new BinaryFormatter();
        //IFormatter formatter = new SoapFormatter();
            
        Test.SerializeItem(fileName, formatter); // Serialize an instance of the class.
        Test.DeserializeItem(fileName, formatter); // Deserialize the instance.
        Console.WriteLine("Done");
        Console.ReadLine();
    }

    public static void SerializeItem(string fileName, IFormatter formatter)
    {
        // Create an instance of the type and serialize it.
        MyItemType t = new MyItemType();
        t.MyProperty = "Hello World";

        FileStream s = new FileStream(fileName , FileMode.Create);
        formatter.Serialize(s, t);            
        s.Close();
    }


    public static void DeserializeItem(string fileName, IFormatter formatter)
    {
        FileStream s = new FileStream(fileName, FileMode.Open);
        MyItemType t = (MyItemType)formatter.Deserialize(s);
        Console.WriteLine(t.MyProperty);            
    }       
}
Imports System.Text
Imports System.IO

' Add references to Soap and Binary formatters.
Imports System.Runtime.Serialization.Formatters.Binary
Imports System.Runtime.Serialization.Formatters.Soap
Imports System.Runtime.Serialization


<Serializable()> _
Public Class MyItemType
    Implements ISerializable
    ' Empty constructor required to compile.
    Public Sub New()
    End Sub

    ' The value to serialize.
    Private myProperty_value As String

    Public Property MyProperty() As String
        Get
            Return myProperty_value
        End Get
        Set(value As String)
            myProperty_value = value
        End Set
    End Property

    ' Implement this method to serialize data. The method is called 
    ' on serialization.
    Public Sub GetObjectData(info As SerializationInfo, context As StreamingContext) Implements ISerializable.GetObjectData
        ' Use the AddValue method to specify serialized values.
        info.AddValue("props", myProperty_value, GetType(String))

    End Sub

    ' The special constructor is used to deserialize values.
    Public Sub New(info As SerializationInfo, context As StreamingContext)
        ' Reset the property value using the GetValue method.
        myProperty_value = DirectCast(info.GetValue("props", GetType(String)), String)
    End Sub
End Class

' This is a console application. 
Public Class Test


    Public Shared Sub Main()
        ' This is the name of the file holding the data. You can use any file extension you like.
        Dim fileName As String = "dataStuff.myData"

        ' Use a BinaryFormatter or SoapFormatter.
        Dim formatter As IFormatter = New BinaryFormatter()
        ' Dim formatter As IFormatter = New SoapFormatter()

        Test.SerializeItem(fileName, formatter)
        ' Serialize an instance of the class.
        Test.DeserializeItem(fileName, formatter)
        ' Deserialize the instance.
        Console.WriteLine("Done")
        Console.ReadLine()
    End Sub

    Public Shared Sub SerializeItem(fileName As String, formatter As IFormatter)
        ' Create an instance of the type and serialize it.
        Dim myType As New MyItemType()
        myType.MyProperty = "Hello World"

        Dim fs As New FileStream(fileName, FileMode.Create)
        formatter.Serialize(fs, myType)
        fs.Close()
    End Sub


    Public Shared Sub DeserializeItem(fileName As String, formatter As IFormatter)
        Dim fs As New FileStream(fileName, FileMode.Open)

        Dim myType As MyItemType = DirectCast(formatter.Deserialize(fs), MyItemType)
        Console.WriteLine(myType.MyProperty)
    End Sub
End Class

Comentarios

Cualquier clase que se pueda serializar se debe marcar con SerializableAttribute.Any class that might be serialized must be marked with the SerializableAttribute. Si una clase necesita controlar su proceso de serialización, puede implementar la ISerializable interfaz.If a class needs to control its serialization process, it can implement the ISerializable interface. Llama al método GetObjectData en el momento de la serialización y rellena SerializationInfo el proporcionado con todos los datos necesarios para representar el objeto. FormatterThe Formatter calls the GetObjectData at serialization time and populates the supplied SerializationInfo with all the data required to represent the object. Formatter Crea unSerializationInfo con el tipo del objeto en el gráfico.The Formatter creates a SerializationInfo with the type of the object in the graph. Los objetos que necesitan enviar proxies para ellos mismos pueden usar FullTypeName los AssemblyName métodos y SerializationInfo en para cambiar la información transmitida.Objects that need to send proxies for themselves can use the FullTypeName and AssemblyName methods on SerializationInfo to change the transmitted information.

En el caso de la herencia de clases, es posible serializar una clase que deriva de una clase base que implementa ISerializable.In the case of class inheritance, it is possible to serialize a class that derives from a base class that implements ISerializable. En este caso, la clase derivada debe llamar a la implementación de la GetObjectData clase base de dentro GetObjectDatade su implementación de.In this case, the derived class should call the base class implementation of GetObjectData inside its implementation of GetObjectData. De lo contrario, no se serializarán los datos de la clase base.Otherwise, the data from the base class will not be serialized.

La ISerializable interfaz implica un constructor con el constructor Signature (SerializationInfo información, StreamingContext contexto).The ISerializable interface implies a constructor with the signature constructor (SerializationInfo information, StreamingContext context). En el momento de la deserialización, se llama al constructor actual solo después de SerializationInfo que el formateador haya deserializado los datos de.At deserialization time, the current constructor is called only after the data in the SerializationInfo has been deserialized by the formatter. En general, este constructor debe protegerse si la clase no está sellada.In general, this constructor should be protected if the class is not sealed.

No se puede garantizar el orden en el que se deserializan los objetos.The order in which objects are deserialized cannot be guaranteed. Por ejemplo, si un tipo hace referencia a un tipo que aún no se ha deserializado, se producirá una excepción.For example, if one type references a type that has not been deserialized yet, an exception will occur. Si va a crear tipos que tienen estas dependencias, puede solucionar el problema implementando la IDeserializationCallback interfaz y el OnDeserialization método.If you are creating types that have such dependencies, you can work around the problem by implementing the IDeserializationCallback interface and the OnDeserialization method.

La arquitectura de serialización controla los tipos de MarshalByRefObject objeto que se extienden igual Objectque los tipos que extienden.The serialization architecture handles object types that extend MarshalByRefObject the same as types that extend Object. Estos tipos se pueden marcar con SerializableAttribute e implementar la ISerializable interfaz como cualquier otro tipo de objeto.These types can be marked with the SerializableAttribute and implement the ISerializable interface as any other object type. Su estado de objeto se capturará y se conservará en la secuencia.Their object state will be captured and persisted onto the stream.

Cuando estos tipos se utilizan a través System.Runtime.Remotingde, la infraestructura de comunicación remota proporciona un suplente que se adelanta a la MarshalByRefObjectserialización típica y, en su lugar, serializa un proxy en.When these types are being used through System.Runtime.Remoting, the remoting infrastructure provides a surrogate that preempts typical serialization and instead serializes a proxy to the MarshalByRefObject. Un suplente es una aplicación auxiliar que sabe cómo serializar y deserializar objetos de un tipo determinado.A surrogate is a helper that knows how to serialize and deserialize objects of a particular type. El proxy, invisible para el usuario en la mayoría de los casos, será ObjRefde tipo.The proxy, invisible to the user in most cases, will be of type ObjRef.

Como modelo de diseño general, es poco habitual que una clase se marque con el atributo Serializable y se extienda MarshalByRefObject.As a general design pattern, it would be unusual for a class to be both marked with the serializable attribute and extend MarshalByRefObject. Los desarrolladores deben pensar detenidamente en los posibles escenarios de serialización y comunicación remota al combinar estas dos características.Developers should think carefully about the possible serialization and remoting scenarios when combining these two characteristics. Un ejemplo en el que esto podría ser aplicable es MemoryStreamcon.One example where this might be applicable is with a MemoryStream. Mientras que la clase base MemoryStream deStream() se MarshalByRefObjectextiende desde, es posible capturar el estado de un MemoryStream y restaurarlo a su vez.While the base class of MemoryStream (Stream) extends from MarshalByRefObject, it is possible to capture the state of a MemoryStream and restore it at will. Por lo tanto, puede ser significativo para serializar el estado de esta secuencia en una base de datos y restaurarla en un momento posterior en el tiempo.It might, therefore, be meaningful to serialize the state of this stream into a database and restore it at some later point in time. Sin embargo, cuando se usa a través de la comunicación remota, un objeto de este tipo sería el proxy.However, when used through remoting, an object of this type would be proxied.

Para obtener más información sobre la serialización de clases MarshalByRefObjectque extienden, vea. RemotingSurrogateSelectorFor more information about serialization of classes that extend MarshalByRefObject, see RemotingSurrogateSelector. Para obtener más información sobre ISerializablecómo implementar, vea serialización personalizada.For more information about implementing ISerializable, see Custom Serialization.

Notas a los implementadores

Implemente esta interfaz para permitir que un objeto participe en su propia serialización y deserialización.Implement this interface to allow an object to take part in its own serialization and deserialization.

Métodos

GetObjectData(SerializationInfo, StreamingContext)

Llena SerializationInfo con los datos necesarios para serializar el objeto de destino.Populates a SerializationInfo with the data needed to serialize the target object.

Se aplica a

Consulte también: