ViewModelBase

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Linq.Expressions;
using System.Text;

namespace System.Windows.Input
{
    public class ViewModelBase : INotifyPropertyChanged
    {

        public event PropertyChangedEventHandler PropertyChanged;
        public void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }

        /// <summary>
        /// Fires the Notify Property Changed event
        /// </summary>
        public virtual void OnPropertyChanged<T>(Expression<Func<T>> expression)
        {

            string propertyName = GetPropertyName(expression);
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null)
                handler(this, new PropertyChangedEventArgs(propertyName));
        }

        /// <summary>
        /// Gets the string name for the property
        /// </summary>
        protected virtual string GetPropertyName<T>(Expression<Func<T>> expression)
        {
            if (expression.NodeType != ExpressionType.Lambda)
            {
                throw new ArgumentException("Value must be a lamda expression", "expression");
            }

            if (!(expression.Body is MemberExpression))
            {
                throw new ArgumentException("The body of the expression must be a memberref", "expression");
            }

            MemberExpression memberExpression = (MemberExpression)expression.Body;
            return memberExpression.Member.Name;
        }
    }


}