Design patterns – 1 Singleton

Design patterns – 1 Singleton

Full initialization

public class Singleton

    {

        private static readonly Singleton _instance = new Singleton();

        private Singleton()

        { }

        public static Singleton GetInstance()

        {

            return _instance;

        }

    }

Lazy initialization

public class Singleton

    {

        private static Singleton _instance; 
  
        private Singleton()

        { } 

        public static Singleton GetInstance()

        {

            if (_instance  == null)

                _instance  = new Singleton();

            return _instance ;

        }

      }

Exemple :

Form1

private void button1_Click(object sender, EventArgs e)

        {

            Singleton.GetInstance().Message = "mon message";

            MessageBox.Show(Singleton.GetInstance().Message);

            Form2 oForm2 = new Form2();

            oForm2.ShowDialog();

        }

Form2

 private void button1_Click(object sender, EventArgs e)

        {

            MessageBox.Show(Singleton.GetInstance().Message);

        }

Singleton utilisé

public class Singleton

    {

        private static readonly Singleton _instance = new Singleton();

        public string Message;

        private Singleton()

        { }

        public static Singleton GetInstance()

        {

            return _instance;

        }

    }

http://webman.developpez.com/articles/dotnet/patterns/singleton/