Le blog de Michael Schouveller

    public string FirstName
    {
        get { return _firstName; }
        set { _firstName = value; }
    }

    public string SurName
    {
        get { return _surName; }
        set { _surName = value; }
    }

    public int? Age
    {
        get { return _age == null ? 0 : _age; }
        set { _age = value; }
    }

    public Object Clone()
    {
        return this.MemberwiseClone();
    }
}

un exemple d'exécution:

Person p1 = new Person("Schouveller", "Michael", 28);
Person p2 = null;
Person p3 = null;

Console.WriteLine("P1: Firstname = {0} Surname = {1} Age = {2}", p1.FirstName, p1.SurName, p1.Age.ToString());

p2 = p1;
p2.Age = 33;
p3 = (Person)p1.Clone();
p3.Age = 50;

Console.WriteLine("P1: Firstname = {0} Surname = {1} Age = {2}", p1.FirstName, p1.SurName, p1.Age.ToString());
Console.WriteLine("P2: Firstname = {0} Surname = {1} Age = {2}", p2.FirstName, p2.SurName, p2.Age.ToString());
Console.WriteLine("P1: Firstname = {0} Surname = {1} Age = {2}", p1.FirstName, p1.SurName, p1.Age.ToString());
Console.WriteLine("P3: Firstname = {0} Surname = {1} Age = {2}", p3.FirstName, p3.SurName, p3.Age.ToString());

Le résultat donne ceci

Notez que l'age du 3ème P1 vaut toujours 33 et que celui de P3 vaut lui 50.
P3 et P1 n'ont donc plus la même référence