Create base class for Notifiy

 public class BaseViewModel : INotifyPropertyChanged
    {
        private Frame frame { get { return App.myFrame; } }

        public event PropertyChangedEventHandler PropertyChanged;

        protected bool SetProperty<T>(ref T storage, T value, [CallerMemberName] String propertyName = null)
        {
            if (Object.Equals(storage, value))
            {
                return false;
            }
            storage = value;
            this.OnPropertyChanged(propertyName);
            return true;
        }

        protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            var eventHandler = this.PropertyChanged;
            if (eventHandler != null)
            {
                try
                {
                    eventHandler(this, new PropertyChangedEventArgs(propertyName));

                }
                catch (Exception propExp)
                {
                    LoggingHelper.ExceptionLogging(propExp, "OnPropertyChanged");
                }
            }
        }      


    }