Implementing Deep Cloning via Serializing objects

Introduction

I was looking around on The Code Project and saw an article talking about the different implementation styles for deep cloning an object. The article referred to an article using Reflection for Deep Cloning an object, but had no article to reference for using Serialization.

Using the Code

This is a helper class that can be used to perform a deep copy of an object:

using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;     
      
/// <summary>
/// Provides a method for performing a deep copy of an object.
/// Binary Serialization is used to perform the copy.
/// </summary>
public static class ObjectCopier
{
 /// <summary>
 /// Perform a deep Copy of the object.
 /// </summary>
 /// <typeparam name="T">The type of object being copied.</typeparam>
 /// <param name="source">The object instance to copy.</param>
 /// <returns>The copied object.</returns>
 public static T Clone<T>(T source)
 {
  if (!typeof(T).IsSerializable)
  {
    throw new ArgumentException("The type must be serializable.", "source");
  }
  
  // Don't serialize a null object, simply return the default for that object
  if (Object.ReferenceEquals(source, null))
  {
    return default(T);
  }

  IFormatter formatter = new BinaryFormatter();
  Stream stream = new MemoryStream();
  using (stream)
  {
    formatter.Serialize(stream, source);
    stream.Seek(0, SeekOrigin.Begin);
    return (T)formatter.Deserialize(stream);
  }
 }
}

Usage of this class becomes ObjectCopier.Clone(objectBeingCloned);.

Points of Interest

In case you prefer to use the new Extension methods of C# 3.0, change the method to have the following signature:

   public static T Clone<T>(this T source)
   {
      ...
   }

Now the method call simply becomes objectBeingCloned.Clone();.

History

• 22^nd February, 2008: Version 1.0: Initial release