Information
The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.

NonSerializedAttribute Class

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

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

[AttributeUsageAttribute(AttributeTargets.Field, Inherited=false)] 
[ComVisibleAttribute(true)] 
public sealed class NonSerializedAttribute : Attribute
/** @attribute AttributeUsageAttribute(AttributeTargets.Field, Inherited=false) */ 
/** @attribute ComVisibleAttribute(true) */ 
public final class NonSerializedAttribute extends Attribute
AttributeUsageAttribute(AttributeTargets.Field, Inherited=false) 
ComVisibleAttribute(true) 
public final class NonSerializedAttribute extends Attribute

When using the BinaryFormatter or SoapFormatter classes to serialize an object, use the NonSerializedAttribute attribute to prevent a field from being serialized. For example, you can use this attribute to prevent the serialization of sensitive data.

The target objects for the NonSerializedAttribute attribute are public and private fields of a serializable class. By default, classes are not serializable unless they are marked with SerializableAttribute. During the serialization process all the public and private fields of a class are serialized by default. Fields marked with NonSerializedAttribute are excluded during serialization. If you are using the XmlSerializer class to serialize an object, use the XmlIgnoreAttribute class to get the same functionality. Alternatively, implement the ISerializable interface to explicitly control the serialization process. Note that classes that implement ISerializable must still be marked with SerializableAttribute.

To apply the NonSerializedAttribute class to an event, set the attribute location to field, as shown in the following C# code.

[field:NonSerializedAttribute()] 
public event ChangedEventHandler Changed;

If a field is not serialized, but it still requires a default value that must be supplied after deserialization, you can create a method that supplies the field with a value, then apply the OnDeserializedAttribute to the method.

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

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.

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();

      Console.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();

      Console.WriteLine("");
      Console.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() {

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

import System.*;
import System.IO.*;
import System.Runtime.Serialization.*;
import System.Runtime.Serialization.Formatters.Soap.*;
//import System.Runtime.Serialization.Formatters.Binary;

public class Test
{
    public static void main(String[] args)
    {        
        //Creates a new TestSimpleObject object.
        TestSimpleObject obj = new TestSimpleObject();
        Console.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();
        Console.WriteLine("");
        Console.WriteLine("After deserialization the object contains: ");
        obj.Print();
    } //main
} //Test

// A test object that needs to be serialized.
/** @attribute Serializable()
 */
public class TestSimpleObject
{
    public int member1;
    public String member2;
    public String member3;
    public double member4;

    // A field that is not serialized.
    /** @attribute NonSerialized()
     */
    public String member5;

    public TestSimpleObject()
    {
        member1 = 11;
        member2 = "hello";
        member3 = "hello";
        member4 = 3.14159265;
        member5 = "hello world!";
    } //TestSimpleObject

    public void Print()
    {
        Console.WriteLine("member1 = '{0}'", (System.Int32)member1);
        Console.WriteLine("member2 = '{0}'", member2);
        Console.WriteLine("member3 = '{0}'", member3);
        Console.WriteLine("member4 = '{0}'", (System.Double)member4);
        Console.WriteLine("member5 = '{0}'", member5);
    } //Print
} //TestSimpleObject

System.Object
   System.Attribute
    System.NonSerializedAttribute

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0
Was this page helpful?
(1500 characters remaining)
Thank you for your feedback

Community Additions

Show:
© 2014 Microsoft