ExtensionDataObject is not Marked as Serializable

If you use Data Contracts, then probably your classes implement the IExtensibleDataObject interface to allow (de)serialization of different versions of the data contract. I won’t go into details about the use of ExtensionDataObject, the type of the ExtensionData property you need to implement. I just want to point out a possible scenario, using sample code similar to that of MSDN:

    1: using System;
    2: using System.Runtime.Serialization;
    3: using System.Runtime.Serialization.Formatters.Binary;
    4:  
    5: namespace Test
    6: {
    7:     [Serializable]
    8:     [DataContract]
    9:     public class Person : IExtensibleDataObject
   10:     {
   11:         private ExtensionDataObject extensionData;
   12:  
   13:         public ExtensionDataObject ExtensionData
   14:         {
   15:             get
   16:             {
   17:                 return extensionData;
   18:             }
   19:             set
   20:             {
   21:                 extensionData = value;
   22:             }
   23:         }
   24:  
   25:         [DataMember]
   26:         public string Name;
   27:     }
   28:  
   29:     class Program
   30:     {
   31:         static void Main(string[] args)
   32:         {
   33:             try
   34:             {
   35:                 new BinaryFormatter().Serialize(Console.OpenStandardOutput(), new Person());
   36:             }
   37:             catch (Exception ex)
   38:             {
   39:                 Console.WriteLine(ex);
   40:             }
   41:         }
   42:     }
   43: }

If you serialize an object of the type used in this example, Person, using a BinaryFormatter, you will get the following exception:

System.Runtime.Serialization.SerializationException: Type 'System.Runtime.Serialization.ExtensionDataObject' in Assembly 'System.Runtime.Serialization, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable.

The solution is to mark the private extensionData field as non-serialized:

    1: [NonSerialized]
    2: private ExtensionDataObject extensionData;

Comments

• Anonymous
  April 03, 2012
  Thanks its very usefully

• Anonymous
  March 04, 2013
  Thanks, this was what I needed to solve my problem.

• Anonymous
  March 06, 2013
  Glad it helped :)

• Anonymous
  March 27, 2013
  But this way you're defeating the purpose of IExtensibleDataObject in the first place... It would be far better if you would just implement the "On serialize" (constructor with SerializationInfo & StreamingContext arguments) and "On deserialize" (GetObjectData()) methods of ISerializable interface, and handle the binary serialization yourself by manually adding the ExtensionDataObject serialized via DataContract, and the rest with binary serialization. That way you can keep the functionallity of IExtensibleDataObject and binary serialization together, without breaking anything.

• Anonymous
  June 06, 2014
  Thank you so much! Solved my problem ;D