notify property changed with expression

propertychangedbase.cs

 class PropertyChangeBase : INotifyPropertyChanged
    {
        protected void SignalChanged<T>(Expression<Func<T>> exp)
        {
            if (exp.Body.NodeType == ExpressionType.MemberAccess)
            {
                var name = (exp.Body as MemberExpression).Member.Name;
                PropertyChanged(this, new PropertyChangedEventArgs(name));
            }
            else
                throw new Exception("Unexpected expression");
        }

        #region INotifyPropertyChanged Members

        public event PropertyChangedEventHandler PropertyChanged =  delegate { };

        #endregion
    }