Observer Pattern

public class Subject
    {
        List<IObserver> _subjects = new List<IObserver>();
        string _message = string.Empty;
        public void Subscribe(IObserver Subject)
        {
            _subjects.Add(Subject);
        }
        private void NotifySubscriber()
        {
            _subjects.ForEach(subject => subject.UpdateState());
        }
        public string GetMessage()
        {
            return _message;
        }
        public void SetMessage(string Message)
        {
            _message = Message;
            NotifySubscriber();
        }
    }

    public interface IObserver
    {
        Subject subject { get; set; }
        void UpdateState();
    }

    public class Subscriber1 : IObserver
    {
        public Subscriber1(Subject OSubject)
        {
            this.subject = OSubject;
            this.subject.Subscribe(this);
        }
        public Subject subject { get; set; }

        public void UpdateState()
        {
            Console.WriteLine("Subscriber 1 is notified with value: " + subject.GetMessage());
        }
    }
    public class Subscriber2 : IObserver
    {
        public Subscriber2(Subject OSubject)
        {
            this.subject = OSubject;
            this.subject.Subscribe(this);
        }
        public Subject subject { get; set; }

        public void UpdateState()
        {
            Console.WriteLine("Subscriber 2 is notified with value: " + subject.GetMessage());
        }
    }
//Consume Observer pattern
            Subject oSubject = new Subject();

            Subscriber1 osub1 = new Subscriber1(oSubject);
            Subscriber2 osub2 = new Subscriber2(oSubject);

            Console.WriteLine("====This is a test message 1====");
            oSubject.SetMessage("First message from Subject");
            Console.WriteLine("====This is a test message 2====");
            oSubject.SetMessage("Second message from Subject");
            Console.ReadLine();