//File:Window.xaml.cs using System; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Media; using System.Windows.Shapes; namespace WpfApplication1{ public partial class Window1 : Window { public Window1() { InitializeComponent(); } void button_Click(object sender, RoutedEventArgs e) { MessageBox.Show("You", "Nice!"); } } }