<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="AboutDialog" ListBox.SelectionChanged="ListBox_SelectionChanged" Button.Click="Button_Click" Title="About WPF Unleashed" SizeToContent="WidthAndHeight" Background="OrangeRed"> <StackPanel> <Label FontWeight="Bold" FontSize="20" Foreground="White"> WPF </Label> <Label>License</Label> <Label>Installed Dll:</Label> <ListBox> <ListBoxItem>1</ListBoxItem> <ListBoxItem>2</ListBoxItem> <ListBoxItem>3</ListBoxItem> <ListBoxItem>4</ListBoxItem> <ListBoxItem>5</ListBoxItem> <ListBoxItem>6</ListBoxItem> <ListBoxItem>7</ListBoxItem> <ListBoxItem>8</ListBoxItem> <ListBoxItem>9</ListBoxItem> </ListBox> <StackPanel Orientation="Horizontal" HorizontalAlignment="Center"> <Button MinWidth="75" Margin="10">Help</Button> <Button MinWidth="75" Margin="10">OK</Button> </StackPanel> <StatusBar>test</StatusBar> </StackPanel> </Window> //File:Window.xaml.cs using System.Windows; using System.Windows.Controls; public partial class AboutDialog : Window { public AboutDialog() { InitializeComponent(); } void ListBox_SelectionChanged(object sender, SelectionChangedEventArgs e) { if (e.AddedItems.Count > 0) MessageBox.Show("You just selected " + e.AddedItems[0]); } void Button_Click(object sender, RoutedEventArgs e) { MessageBox.Show("You just clicked " + e.Source); } }