WPF C# Tutorial

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


//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 WpfApplication1
{
    public partial class Window1 : System.Windows.Window
    {
        public Window1()
        {
            InitializeComponent();
            CommandBinding redoCommandBinding = new CommandBinding(ApplicationCommands.Redo);
            redoCommandBinding.CanExecute += RedoCommandCanExecute;
            CommandBindings.Add(redoCommandBinding);
        }
        void RedoCommandCanExecute(object sender, CanExecuteRoutedEventArgs e)
        {
            e.CanExecute =  DateTime.Now.Second % 2 > 1;
        }
    }
}