System Namespace

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Indicates that a field of a serializable class should not be serialized. This class cannot be inherited.

NonSerializedAttribute Class Members

Show Inherited Members

Constructors Visibility Constructor Parameters public NonSerializedAttribute ( )

The target objects for the NonSerializedAttribute are public and private fields of a serializable class. By default, classes are not serializable unless they are marked with the SerializableAttribute. During the serialization process all the public and private fields of a class are serialized by default. Fields that are not to be serialized can be marked with the NonSerializedAttribute, which causes the serialization process to exclude the target field during serialization. Alternatively, implement the ISerializable interface to explicitly control the serialization process. Note that classes which implement ISerializable still need to be marked with the SerializableAttribute.

For more information about using attributes, see Extending Metadata Using Attributes.

[ Visual Basic, C# ] The following example demonstrates serialization of an object marked with the SerializableAttribute attribute, and the behavior of a field marked with the NonSerializedAttribute in the serialized object. To use the BinaryFormatter instead of the SoapFormatter, uncomment the appropriate lines.

[ VB ]
Imports System
Imports System.IO
Imports System.Runtime.Serialization
Imports System.Runtime.Serialization.Formatters.Soap

''Imports System.Runtime.Serialization.Formatters.Binary


Public Class Test
  
   Public Shared Sub Main ( )
     
      ' Creates a new TestSimpleObject object.
      Dim obj As New TestSimpleObject ( )
     
      Response.WriteLine ( "Before serialization the object contains: " )
      obj.Print ( )
     
      ' Opens a file and serializes the object into it in binary format.
      Dim stream As Stream = File.Open ( "data.xml", FileMode.Create )
      Dim formatter As New SoapFormatter ( )
     
      ''Dim formatter As New BinaryFormatter ( )

      formatter.Serialize ( stream, obj )
      stream.Close ( )
     
      ' Empties obj.
      obj = Nothing
     
      ' Opens file "data.xml" and deserializes the object from it.
      stream = File.Open ( "data.xml", FileMode.Open )
      formatter = New SoapFormatter ( )

      ''formatter = New BinaryFormatter ( )

      obj = CType ( formatter.Deserialize ( stream ), TestSimpleObject )
      stream.Close ( )
     
      Response.WriteLine ( "" )
      Response.WriteLine ( "After deserialization the object contains: " )
      obj.Print ( )

   End Sub 'Main

End Class 'Test


' A test object that needs to be serialized.
<Serializable ( ) > Public Class TestSimpleObject
  
   Public member1 As Integer
   Public member2 As String
   Public member3 As String
   Public member4 As Double
  
   ' A member that is not serialized.
   <NonSerialized ( ) > Public member5 As String 
 
  
   Public Sub New ( )    
      member1 = 11
      member2 = "hello"
      member3 = "hello"
      member4 = 3.14159265
      member5 = "hello world!"
   End Sub 'New
     
  
   Public Sub Print ( )     
      Response.WriteLine ( "member1 = '{0}'", member1 )
      Response.WriteLine ( "member2 = '{0}'", member2 )
      Response.WriteLine ( "member3 = '{0}'", member3 )
      Response.WriteLine ( "member4 = '{0}'", member4 )
      Response.WriteLine ( "member5 = '{0}'", member5 )
   End Sub 'Print

End Class 'TestSimpleObject

[ C# ]
using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Soap;
//using System.Runtime.Serialization.Formatters.Binary;

public class Test {
   public static void Main ( )  {

      //Creates a new TestSimpleObject object.
      TestSimpleObject obj = new TestSimpleObject ( );

      Response.WriteLine ( "Before serialization the object contains: " );
      obj.Print ( );

      //Opens a file and serializes the object into it in binary format.
      Stream stream = File.Open ( "data.xml", FileMode.Create );
      SoapFormatter formatter = new SoapFormatter ( );

      //BinaryFormatter formatter = new BinaryFormatter ( );

      formatter.Serialize ( stream, obj );
      stream.Close ( );
  
      //Empties obj.
      obj = null;
  
      //Opens file "data.xml" and deserializes the object from it.
      stream = File.Open ( "data.xml", FileMode.Open );
      formatter = new SoapFormatter ( );

      //formatter = new BinaryFormatter ( );

      obj = ( TestSimpleObject ) formatter.Deserialize ( stream );
      stream.Close ( );

      Response.WriteLine ( "" );
      Response.WriteLine ( "After deserialization the object contains: " );
      obj.Print ( );
   }
}


// A test object that needs to be serialized.
[ Serializable ( ) ]     
public class TestSimpleObject  {

    public int member1;
    public string member2;
    public string member3;
    public double member4;
   
    // A field that is not serialized.
    [ NonSerialized ( ) ] public string member5;
   
    public TestSimpleObject ( ) {

        member1 = 11;
        member2 = "hello";
        member3 = "hello";
        member4 = 3.14159265;
        member5 = "hello world!";
    }


    public void Print ( ) {

        Response.WriteLine ( "member1 = '{0}'", member1 );
        Response.WriteLine ( "member2 = '{0}'", member2 );
        Response.WriteLine ( "member3 = '{0}'", member3 );
        Response.WriteLine ( "member4 = '{0}'", member4 );
        Response.WriteLine ( "member5 = '{0}'", member5 );
    }
}

SerializableAttribute   Attribute   ISerializable

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