SerializationInfo.GetValue(String, Type) Método

Definición

Espacio de nombres:

System.Runtime.Serialization

Ensamblado:

System.Runtime.dll

Source:

SerializationInfo.cs

Recupera un valor del almacén SerializationInfo.

public:
 System::Object ^ GetValue(System::String ^ name, Type ^ type);

public object? GetValue (string name, Type type);

member this.GetValue : string * Type -> obj

Public Function GetValue (name As String, type As Type) As Object

Parámetros

name

String

Nombre asociado con el valor que se va a recuperar.

type

Type

Tipo Type del valor que se va a recuperar. Si el valor almacenado no se puede convertir en este tipo, el sistema produce InvalidCastException.

Devoluciones

Object

Objeto del Type especificado que está asociado a name.

Excepciones

ArgumentNullException

name o type es null.

InvalidCastException

El valor asociado a name no se puede convertir en type.

SerializationException

El elemento con el nombre especificado no se encuentra en la instancia actual.

Ejemplos

En el GetValue ejemplo de código siguiente se muestra el uso del método :

// A serializable LinkedList example.  For the full LinkedList implementation
// see the Serialization sample.
[Serializable]
ref class LinkedList: public ISerializable
{
private:
   Node^ m_head;
   Node^ m_tail;

   // Serializes the object.
public:
   virtual void GetObjectData( SerializationInfo^ info, StreamingContext /*context*/ )
   {
      // Stores the m_head and m_tail references in the SerializationInfo info.
      info->AddValue( "head", m_head, m_head->GetType() );
      info->AddValue( "tail", m_tail, m_tail->GetType() );
   }

   // Constructor that is called automatically during deserialization.
private:
   // Reconstructs the object from the information in SerializationInfo info
   LinkedList( SerializationInfo^ info, StreamingContext /*context*/ )
   {
      Node^ temp = gcnew Node( 0 );
      // Retrieves the values of Type temp.GetType() from SerializationInfo info
      m_head = dynamic_cast<Node^>(info->GetValue( "head", temp->GetType() ));
      m_tail = dynamic_cast<Node^>(info->GetValue( "tail", temp->GetType() ));
   }
};

// A serializable LinkedList example.  For the full LinkedList implementation
// see the Serialization sample.
[Serializable()]
class LinkedList: ISerializable {

   public static void Main() {}

   Node m_head = null;
   Node m_tail = null;

   // Serializes the object.
   public void GetObjectData(SerializationInfo info, StreamingContext context){
      // Stores the m_head and m_tail references in the SerializationInfo info.
      info.AddValue("head", m_head, m_head.GetType());
      info.AddValue("tail", m_tail, m_tail.GetType());
   }

   // Constructor that is called automatically during deserialization.
   // Reconstructs the object from the information in SerializationInfo info
   private LinkedList(SerializationInfo info, StreamingContext context)
   {
      Node temp = new Node(0);
      // Retrieves the values of Type temp.GetType() from SerializationInfo info
      m_head = (Node)info.GetValue("head", temp.GetType());
      m_tail = (Node)info.GetValue("tail", temp.GetType());
   }
}

' A serializable LinkedList example.  For the full LinkedList implementation
' see the Serialization sample.
<Serializable()> Class LinkedList
    Implements ISerializable

    Public Shared Sub Main()
    End Sub

    Private m_head As Node = Nothing
    Private m_tail As Node = Nothing    
    
    ' Serializes the object.
    Public Sub GetObjectData(info As SerializationInfo, _
    context As StreamingContext) Implements ISerializable.GetObjectData
    
        ' Stores the m_head and m_tail references in the SerializationInfo info.
        info.AddValue("head", m_head, m_head.GetType())
        info.AddValue("tail", m_tail, m_tail.GetType())
    End Sub
    
    
    ' Constructor that is called automatically during deserialization.
    ' Reconstructs the object from the information in SerializationInfo info.
    Private Sub New(info As SerializationInfo, context As StreamingContext)
        Dim temp As New Node(0)
        ' Retrieves the values of Type temp.GetType() from SerializationInfo info.
        m_head = CType(info.GetValue("head", temp.GetType()), Node)
        m_tail = CType(info.GetValue("tail", temp.GetType()), Node)
    End Sub
End Class

Comentarios

Si los datos almacenados en SerializationInfo es del tipo solicitado (o una de sus clases derivadas), ese valor se devuelve directamente. De lo contrario, IFormatterConverter.Convert se llama a para convertirlo en el tipo adecuado.

El valor devuelto por el GetValue método siempre se puede convertir de forma segura al tipo especificado en el type parámetro .