gistfile1.cs

    public class Demo : INotifyPropertyChanged
    {
        protected void SetValue<T>(T value, ref T container, [CallerMemberName] string propertyName = "")
        {
            if (value.Equals(container))
                return;

            container = value;
            OnPropertyChanged(propertyName);
        }


        public event PropertyChangedEventHandler PropertyChanged;

        private void OnPropertyChanged(string propertyName)
        {
            var pc = PropertyChanged;
            if (pc != null)
                pc.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    public class ConcreteDemo : Demo
    {
        private string _value;
        public string Value
        {
            get { return _value; }
            set { SetValue(value, ref _value); }
        }
    }