ServiceBehaviorAttribute.IgnoreExtensionDataObject Property


Gets or sets a value that specifies whether to send unknown serialization data onto the wire.

 property bool IgnoreExtensionDataObject { bool get(); void set(bool value); };
public bool IgnoreExtensionDataObject { get; set; }
member this.IgnoreExtensionDataObject : bool with get, set
Public Property IgnoreExtensionDataObject As Boolean

Property Value


true if unknown serialization data is never sent; otherwise, false. The default is false.


The following example shows the use of IgnoreExtensionDataObject and an implementation of IExtensibleDataObject. In this sample, with IgnoreExtensionDataObject set to false, the extra data that the client knows about is round-tripped back to the client.

using System;
using System.Collections.Generic;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
using System.Xml;

namespace Microsoft.WCF.Documentation
  [ServiceContract(Namespace = "http://microsoft.wcf.documentation")]
  public interface ISampleService{
    Person SampleMethod(Person personParam);

  [DataContract(Name="OriginalPerson", Namespace="http://microsoft.wcf.documentation")]
  public class Person : IExtensibleDataObject
    public string firstName;
    public string lastName;
    public string Message;
    public XmlNode[] Blob;

    #region IExtensibleDataObject Members
    private ExtensionDataObject data = null;

    public ExtensionDataObject ExtensionData
      { = value;

  class SampleService : ISampleService
  #region ISampleService Members
    public Person SampleMethod(Person msg)

      msg.lastName = "First Name";
      msg.firstName = "Last Name";
      msg.Message = "This is the Reply message.";
        return msg;


If a type implements the IExtensibleDataObject interface, it stores any extra data it doesn't know about that comes over the wire when deserializing into that type. For example, if a type Person has members FirstName and LastName, and an element called PhoneNumber comes in, it is stored. When later serializing the type, PhoneNumber will be re-emitted. The problem is that the schema for Person exported by that service only has FirstName and LastName, so Windows Communication Foundation (WCF) generates a schema-invalid instance! If strict schema compliance is important, you can set IgnoreExtensionDataObject to true to turn this re-emitting behavior off.

Regardless IgnoreExtensionDataObject setting, WCF always processes known data (both in and out) and does not throw exceptions when extra data comes in. You can also set this property using the <dataContractSerializer> element in an application configuration file.

Applies to