SerializationInfo.GetValue(String, Type) Method

Definition

Namespace:

System.Runtime.Serialization

Assembly:

System.Runtime.dll

Source:

SerializationInfo.cs

Retrieves a value from the SerializationInfo store.

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

Parameters

name

String

The name associated with the value to retrieve.

type

Type

The Type of the value to retrieve. If the stored value cannot be converted to this type, the system will throw a InvalidCastException.

Returns

Object

The object of the specified Type associated with name.

Exceptions

ArgumentNullException

name or type is null.

InvalidCastException

The value associated with name cannot be converted to type.

SerializationException

An element with the specified name is not found in the current instance.

Examples

The following code example demonstrates the use of the GetValue method:

// 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

Remarks

If the data stored in the SerializationInfo is of the type requested (or one of its derived classes), that value is returned directly. Otherwise, IFormatterConverter.Convert is called to convert it to the appropriate type.

The value returned by the GetValue method can always be safely cast to the type specified in the type parameter.