<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">
    <DockPanel LastChildFill="True">
        <TextBox DockPanel.Dock="Top" TextInput="TextBox_TextEvent" />
        <TextBox Name="txtLog" HorizontalAlignment="Stretch" 
                 IsReadOnly="True" VerticalScrollBarVisibility="Visible"/>
    </DockPanel>
</Window>

//File:Window.xaml.cs
using System;
using System.Windows;
using System.Windows.Input;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }

        private void TextBox_TextEvent(object sender,TextCompositionEventArgs e)
        {
            String msg = String.Format("{0} - {1}
",
                e.RoutedEvent.Name, e.Text);

            txtLog.Text += msg;
            txtLog.ScrollToEnd();
        }
    }
}

   
    
     

   
  



<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">
    <DockPanel LastChildFill="True">
        <TextBox DockPanel.Dock="Top" PreviewTextInput="TextBox_TextEvent"/>
        <TextBox Name="txtLog" HorizontalAlignment="Stretch" 
                 IsReadOnly="True" VerticalScrollBarVisibility="Visible"/>
    </DockPanel>
</Window>

//File:Window.xaml.cs
using System;
using System.Windows;
using System.Windows.Input;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }

        private void TextBox_TextEvent(object sender,TextCompositionEventArgs e)
        {
            String msg = String.Format("{0} - {1}
", e.RoutedEvent.Name, e.Text);

            txtLog.Text += msg;
            txtLog.ScrollToEnd();
        }
    }
}

   
    
     

   
  

<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">
    <DockPanel LastChildFill="True">
        <TextBox DockPanel.Dock="Top" PreviewTextInput="TextBox_TextEvent"/>
        <TextBox Name="txtLog" HorizontalAlignment="Stretch" 
                 IsReadOnly="True" VerticalScrollBarVisibility="Visible"/>
    </DockPanel>
</Window>

//File:Window.xaml.cs
using System;
using System.Windows;
using System.Windows.Input;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }

        private void TextBox_TextEvent(object sender,TextCompositionEventArgs e)
        {
            String msg = String.Format("{0} - {1}
", e.RoutedEvent.Name, e.Text);

            txtLog.Text += msg;
            txtLog.ScrollToEnd();
        }
    }
}

   
    
     

   
  


<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">
    <DockPanel LastChildFill="True">
        <TextBox DockPanel.Dock="Top" KeyDown="TextBox_KeyEvent" />
        <TextBox Name="txtLog" HorizontalAlignment="Stretch" 
                 IsReadOnly="True" VerticalScrollBarVisibility="Visible"/>
    </DockPanel>
</Window>

//File:Window.xaml.cs
using System;
using System.Windows;
using System.Windows.Input;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }

        private void TextBox_KeyEvent(object sender, KeyEventArgs e)
        {
            String msg = String.Format("{0} - {1}
",e.RoutedEvent.Name, e.Key);

            txtLog.Text += msg;
            txtLog.ScrollToEnd();
        }
    }
}

   
    
     

   
  


<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">
    <DockPanel LastChildFill="True">
        <TextBox DockPanel.Dock="Top" PreviewKeyUp="TextBox_KeyEvent" />
        <TextBox Name="txtLog" HorizontalAlignment="Stretch" IsReadOnly="True" VerticalScrollBarVisibility="Visible"/>
    </DockPanel>
</Window>

//File:Window.xaml.cs
using System;
using System.Windows;
using System.Windows.Input;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }

        private void TextBox_KeyEvent(object sender, KeyEventArgs e)
        {
            String msg = String.Format("{0} - {1}
",e.RoutedEvent.Name, e.Key);

            txtLog.Text += msg;
            txtLog.ScrollToEnd();
        }

    }
}

   
    
     

   
  


<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">
    <DockPanel LastChildFill="True">
        <TextBox DockPanel.Dock="Top" KeyUp="TextBox_KeyEvent" />
        <TextBox Name="txtLog" HorizontalAlignment="Stretch" 
                 IsReadOnly="True" VerticalScrollBarVisibility="Visible"/>
    </DockPanel>
</Window>

//File:Window.xaml.cs
using System;
using System.Windows;
using System.Windows.Input;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }

        private void TextBox_KeyEvent(object sender, KeyEventArgs e)
        {
            String msg = String.Format("{0} - {1}
",e.RoutedEvent.Name, e.Key);

            txtLog.Text += msg;
            txtLog.ScrollToEnd();
        }
    }
}

   
    
     

   
  

<Window x:Class="WpfApplication1.Window1"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  Title="Window1" Height="300" Width="300">
  <Grid>
    <StackPanel>
      <TextBox x:Name="uv" PreviewKeyDown="TextBox_PreviewKeyDown" />

    </StackPanel>
  </Grid>
</Window>


//File:Window1.xaml.cs
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
            DataContext = this;
        }

        //
        private void TextBox_PreviewKeyDown(object sender, RoutedEventArgs e)
        {
            TextBox textBox = sender as TextBox;

            if (textBox != null)
            {
                textBox.Foreground = Brushes.Firebrick;
            }
        }
    }
}