WPF C#

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="SimpleDocument" Height="300" Width="300">
    
      
        
        
        
      

      
        
          
          
          
          
          
          
        
      
      
        
        New
          Open
          Save        
      

        
          Cut
          Copy
          Paste
          
        

      
                     TextWrapping="Wrap" AcceptsReturn="True"
               TextChanged="txt_TextChanged">
    


//File:Window.xaml.cs
using System;
using System.Collections.Generic;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
namespace Commands
{
    public partial class SimpleDocument : System.Windows.Window
    {
        public SimpleDocument()
        {
            InitializeComponent();
            CommandBinding binding;
            binding = new CommandBinding(ApplicationCommands.New);
            binding.Executed += NewCommand;
            this.CommandBindings.Add(binding);
            binding = new CommandBinding(ApplicationCommands.Open);
            binding.Executed += OpenCommand;
            this.CommandBindings.Add(binding);
            binding = new CommandBinding(ApplicationCommands.Save);
            binding.Executed += SaveCommand_Executed;
            binding.CanExecute += SaveCommand_CanExecute;
            this.CommandBindings.Add(binding);
        }
        private void NewCommand(object sender, ExecutedRoutedEventArgs e)
        {
            Console.WriteLine("New command triggered with " + e.Source.ToString());
            isDirty = false;          
        }
        private void OpenCommand(object sender, ExecutedRoutedEventArgs e)
        {
            isDirty = false;
        }
        private void SaveCommand_Executed(object sender, ExecutedRoutedEventArgs e)
        {
            Console.WriteLine("Save command triggered with " + e.Source.ToString());
            isDirty = false;
        }
        private bool isDirty = false;
        private void txt_TextChanged(object sender, RoutedEventArgs e)
        {
            isDirty = true;
        }
        private void SaveCommand_CanExecute(object sender, CanExecuteRoutedEventArgs e)
        {            
            e.CanExecute = isDirty;
        }
    }
}