Singleton

public sealed class Singleton

{

    private static Singleton instance = null;

    private static readonly object padlock = new object();

    private Singleton()

    {

    }

    public static Singleton GetInstance()

    {

            lock (padlock)

            {

                if (instance == null)

                {

                    instance = new Singleton();

                }

                return instance;

            }

        }

    }

}