<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="300" Width="300"> <StackPanel> <TextBox AcceptsReturn="True" Height="100" IsReadOnly="True" Name="textBox1" TextAlignment="Left" TextWrapping="Wrap" VerticalScrollBarVisibility="Auto"> Default starting text. </TextBox> <Grid> <Grid.ColumnDefinitions> <ColumnDefinition/> <ColumnDefinition/> <ColumnDefinition/> </Grid.ColumnDefinitions> <RadioButton Checked="AlignmentChecked" Grid.Column="0" HorizontalAlignment="Center" IsChecked="True" Margin="5" Name="leftAlignRadioButton"> Left</RadioButton> <RadioButton Checked="AlignmentChecked" Grid.Column="1" HorizontalAlignment="Center" Margin="5" Name="centerAlignRadioButton"> Center</RadioButton> <RadioButton Checked="AlignmentChecked" Grid.Column="2" HorizontalAlignment="Center" Margin="5" Name="rightAlignRadioButton"> Right</RadioButton> </Grid> </StackPanel> </Window> //File:Window.xaml.cs using System.Windows; using System.Windows.Controls; namespace WpfApplication1 { public partial class Window1 : Window { public Window1() { InitializeComponent(); } private void AlignmentChecked(object sender, RoutedEventArgs e) { RadioButton button = e.OriginalSource as RadioButton; if (e.OriginalSource == leftAlignRadioButton) { textBox1.TextAlignment = TextAlignment.Left; } else if (e.OriginalSource == centerAlignRadioButton) { textBox1.TextAlignment = TextAlignment.Center; } else if (e.OriginalSource == rightAlignRadioButton) { textBox1.TextAlignment = TextAlignment.Right; } textBox1.Focus(); } } }