<Canvas xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:src="clr-namespace:ListBoxEvent" x:Class="ListBoxEvent.Pane1"> <Canvas.Resources> <src:myColors x:Key="Colors"/> </Canvas.Resources> <StackPanel> <TextBox Name="tb" Width="140" Height="30"></TextBox> <ListBox Name="lb" Width="100" Height="55" SelectionChanged="PrintText" SelectionMode="Single"> <ListBoxItem>Item 1</ListBoxItem> <ListBoxItem>Item 2</ListBoxItem> <ListBoxItem>Item 3</ListBoxItem> <ListBoxItem>Item 4</ListBoxItem> <ListBoxItem>Item 5</ListBoxItem> <ListBoxItem>Item 6</ListBoxItem> <ListBoxItem>Item 7</ListBoxItem> <ListBoxItem>Item 8</ListBoxItem> <ListBoxItem>Item 9</ListBoxItem> <ListBoxItem>Item 10</ListBoxItem> </ListBox> </StackPanel> </Canvas> //File:Window.xaml.cs using System; using System.ComponentModel; using System.Windows; using System.Windows.Controls; using System.Windows.Documents; using System.Windows.Navigation; using System.Windows.Shapes; using System.Windows.Data; using System.Windows.Media; using System.Collections.ObjectModel; namespace ListBoxEvent { public class myColors : ObservableCollection<string> { public myColors() { Add("A"); Add("B"); Add("C"); Add("D"); Add("E"); Add("F"); } } public partial class Pane1 : Canvas { public Pane1() : base(){ InitializeComponent(); } void PrintText(object sender, SelectionChangedEventArgs args) { ListBoxItem lbi = ((sender as ListBox).SelectedItem as ListBoxItem); tb.Text = " You selected " + lbi.Content.ToString() + "."; } } }