public class ViewModelBase : INotifyPropertyChanged
    {
        #region interface

        public event PropertyChangedEventHandler PropertyChanged = delegate { };

        #endregion

        public void NotifyOfPropertyChange(string propertyName)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }

        public void NotifyOfPropertyChange<TProperty>(Expression<Func<TProperty>> property)
        {
            var lambda = (LambdaExpression)property;

            MemberExpression memberExpression;
            if (lambda.Body is UnaryExpression)
            {
                var unaryExpression = (UnaryExpression)lambda.Body;
                memberExpression = (MemberExpression)unaryExpression.Operand;
            }
            else
                memberExpression = (MemberExpression)lambda.Body;

            NotifyOfPropertyChange(memberExpression.Member.Name);
        }

        protected bool SetProperty<T>(ref T backingField, T value, string propertyName)
        {
            var changed = !EqualityComparer<T>.Default.Equals(backingField, value);
            if (changed)
            {
                backingField = value;
                NotifyOfPropertyChange(propertyName);
            }
            return changed;
        }
        protected bool SetProperty<T, TProperty>(ref T backingField, T value, Expression<Func<TProperty>> property)
        {
            var changed = !EqualityComparer<T>.Default.Equals(backingField, value);
            if (changed)
            {
                backingField = value;
                NotifyOfPropertyChange(property);
            }
            return changed;
        }
    }