Serialization in C#

Serialization is an easy way to convert an object to a binary representation that can then be e.g. written to disk or sent over a wire.

It's useful e.g. for easy saving of settings to a file.

You can serialize your own classes if you mark them with [Serializable] attribute. This serializes all members of a class, except those marked as [NonSerialized].

.NET offers 2 serializers: binary, SOAP, XML. The difference between binary and SOAP is:

• binary is more efficient (time and memory used)
• binary is completely human-unreadable. SOAP isn't much better.

XML is slightly different:

• it lives in System.Xml.Serialization
• it uses [XmlIgnore] instead of [NonSerialized] and ignores [Serializable]
• it doesn't serialize private class members

An example of serialization/deserialization to a file:

using System.IO;

using System.Diagnostics;

using System.Runtime.Serialization;

using System.Runtime.Serialization.Formatters;

using System.Runtime.Serialization.Formatters.Binary;

 

[Serializable]

public class MySettings {

    public int screenDx;

    public ArrayList recentlyOpenedFiles;

    [NonSerialized]public string dummy;

}

 

public class Settings {

    const int VERSION = 1;

    static void Save(MySettings settings, string fileName) {

            Stream stream = null;

            try {

                IFormatter formatter = new BinaryFormatter();

                stream = new FileStream(fileName, FileMode.Create, FileAccess.Write, FileShare.None);

                formatter.Serialize(stream, VERSION);

                formatter.Serialize(stream, settings);

            } catch {

                // do nothing, just ignore any possible errors

            } finally {

                if (null != stream)

                    stream.Close();

            }

    }

   

    static MySettings Load(string fileNmae) {

        Stream stream = null;

        MySettings settings = null;

        try {

            IFormatter formatter = new BinaryFormatter();

            stream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.None);

            int version = (ArrayList)formatter.Deserialize(stream);

            Debug.Assert(version == VERSION);

            settings = (MySettings)formatter.Deserialize(stream);

        } catch {

            // do nothing, just ignore any possible errors

        } finally {

            if (null != stream)

                stream.Close();

        }

        return settings;

    }

}