C# 2008 Programmer's Reference

Binary Serialization

Consider the following class, BookMark, which is used to stored information about web addresses and their descriptions:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
namespace Serialization {
 class Program {
  static void Main(string[] args) {}
 }
 class BookMark {
  private DateTime _dateCreated;
  public BookMark() {
   _dateCreated = DateTime.Now;
  }
  public DateTime GetDateCreated() {
   return _dateCreated;
  }
  public string URL { get; set; }
  public string Description { get; set; }
  public BookMark NextURL { get; set; }
 }
}

The BookMark class contains properties as well as private variables. The NextURL property links multiple BookMark objects, much like a linked list. Let's now create two BookMark objects and link them:

static void Main(string[] args) {
 BookMark bm1, bm2;
 bm1 = new BookMark {
  URL = 'http://www.amazon.com',
  Description = 'Amazon.com Web site'
 };
 bm2 = new BookMark() {
  URL = 'http://www.wrox.com',
  Description = 'Wrox.com Web site',
  NextURL = null
 };
 //---link the first BookMark to the next---
 bm1.NextURL = bm2;
}

You can serialize the objects into a binary stream by writing the Serialize() function:

static void Main(string[] args) {
 //...
}
static MemoryStream Serialize(BookMark bookMark) {
 MemoryStream ms = new MemoryStream();
 FileStream fs = new FileStream(
  @'C:Bookmarks.dat', FileMode.Create, FileAccess.Write);
 BinaryFormatter formatter = new BinaryFormatter();
 //---serialize to memory stream---
 formatter.Serialize(ms, bookMark);
 ms.Position = 0;
 //---serialize to file stream---
 formatter.Serialize(fs, bookMark);
 return ms;
}

For binary serialization, you need to import the System.Runtime.Serialization.Formatters.Binary namespace.

The Serialize() function takes in a single parameter (the BookMark object to serialize) and returns a MemoryStream object representing the serialized BookMark object. You use the BinaryFormatter class from the System.Runtime.Serialization.Formatters.Binary namespace to serialize an object. One side effect of this function is that it also serializes the BookMark object to file, using the FileStream class.

Before you serialize an object, you need to prefix the class that you want to serialize name with the [Serializable] attribute:

[Serializable]
class BookMark {
 private DateTime _dateCreated;
 public BookMark() {
  _dateCreated = DateTime.Now;
 }
 public DateTime GetDateCreated() {
  return _dateCreated;
 }
 public string URL { get; set; }
 public string Description { get; set; }
 public BookMark NextURL { get; set; }
}

The following statement serializes the bm1 BookMark object, using the Serialize () function:

static void Main(string[] args) {
 BookMark bm1, bm2;
 bm1 = new BookMark {
  URL = 'http://www.amazon.com',
  Description = 'Amazon.com Web site'
 };
 bm2 = new BookMark() {
  URL = 'http://www.wrox.com',