xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="WPF" Height="200" Width="300"> text //File:Window.xaml.csusing 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 Clear_Click(object sender, RoutedEventArgs e) { txtTextBox.Clear(); } private void SelectAll_Click(object sender, RoutedEventArgs e) { txtTextBox.SelectAll(); } private void TextStyle_Click(object sender, RoutedEventArgs e) { if (sender == miNormal) { txtTextBox.FontWeight = FontWeights.Normal; txtTextBox.FontStyle = FontStyles.Normal; } else if (sender == miBold) { txtTextBox.FontWeight = FontWeights.Bold; } else if (sender == miItalic) { txtTextBox.FontStyle = FontStyles.Italic; } } }}