<Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="WPF" Height="170" Width="300"> <StackPanel> <Button Click="btnMessageHeaderButton_Click" Content="Message, Header, and Button" Margin="5" Name="btnMessageHeaderButton" /> </StackPanel> </Window> //File:Window.xaml.cs using System; using System.Collections.Generic; using System.Linq; 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.Navigation; using System.Windows.Shapes; namespace WpfApplication1 { public partial class Window1 : Window { public Window1() { InitializeComponent(); } private void btnMessageHeaderButton_Click(object sender, RoutedEventArgs e) { MessageBox.Show("A MessageBox with a title and buttons.", "WPF", MessageBoxButton.YesNoCancel); } } }