Klawiatura z obrazka - Część 1 - Microsoft Visual C #

<Window x:Class="klawiatura.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Program do pisania" Height="590" Width="772.165" Background="#FFD8F3C5" ResizeMode="NoResize" Icon="obazki/computer-hacked.jpg">
    <Grid Margin="0,-31,16.2,-4.2">
        <Image HorizontalAlignment="Left" Margin="18,202,-0.4,10" Width="732" Source="obazki/keyboardfng.gif"/>
        <Button x:Name="_1btn" Content="Button" HorizontalAlignment="Left" Margin="69,329,0,0" VerticalAlignment="Top" Width="32" Height="33" Opacity="0" Click="_1btn_Click"/>
        <TextBox x:Name="pisanietb" HorizontalAlignment="Left" Height="193" Margin="10,50,-0.4,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="740" Background="#FFEBE6CC" FontSize="20" UndoLimit="20000" Cursor="Arrow" AcceptsReturn="True" HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto"/>
        <Button x:Name="_1btn_Copy" Content="Button" HorizontalAlignment="Left" Margin="69,329,0,0" VerticalAlignment="Top" Width="32" Height="33" Click="_1btn_Click" Opacity="0"/>
        <Button x:Name="_2btn" Content="Button" HorizontalAlignment="Left" Margin="106,329,0,0" VerticalAlignment="Top" Width="32" Height="33" Opacity="0" Click="_2btn_Click"/>
        <Button x:Name="_Enterbtn" Content="Button" HorizontalAlignment="Left" Margin="575,392,0,0" VerticalAlignment="Top" Width="32" Height="33" Opacity="0" Click="_Enterbtn_Click" RenderTransformOrigin="15.21,2.439"/>
        <Button x:Name="_abtn" Content="Button" HorizontalAlignment="Left" Margin="98,406,0,0" VerticalAlignment="Top" Width="32" Height="33" Opacity="0" Click="_abtn_Click" RenderTransformOrigin="1.454,2.828"/>
        <Button x:Name="_caps" Content="Button" HorizontalAlignment="Left" Margin="43,406,0,0" VerticalAlignment="Top" Width="32" Height="33" Opacity="0" Click="_caps_Click" RenderTransformOrigin="1.454,2.828"/>
        <Button x:Name="_backspacebtn" Content="Button" HorizontalAlignment="Left" Margin="585,329,0,0" VerticalAlignment="Top" Width="32" Height="33" Opacity="0" Click="_backspacebtn_Click" RenderTransformOrigin="15.21,2.439"/>

    </Grid>
    <Window.Triggers>
    <EventTrigger RoutedEvent="Button.Click">
        <EventTrigger.Actions>
            <SoundPlayerAction Source="dzwieki/click.wav" />
         </EventTrigger.Actions>
    </EventTrigger>
</Window.Triggers>
</Window>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
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 klawiatura
{
    /// <summary>
    /// Prosta klawiatura generowana ze zdjęcia
    /// </summary>
    public partial class MainWindow : Window
    {
        TextBox BehaveTextbox;
        static bool capsLockwlaczony= false;
        public MainWindow()
        {
            InitializeComponent();
        }

        private void _1btn_Click(object sender, RoutedEventArgs e)
        {
            pisanietb.Text += "1";
        }

        private void _Enterbtn_Click(object sender, RoutedEventArgs e)
        {
            pisanietb.Text += "\r\n";
        }

        private void _2btn_Click(object sender, RoutedEventArgs e)
        {
            pisanietb.Text += "2";
        }

        private void _abtn_Click(object sender, RoutedEventArgs e)
        {
            if(!capsLockwlaczony)
                pisanietb.Text += "a";
            else
                pisanietb.Text += "A";
        }

        private void _caps_Click(object sender, RoutedEventArgs e)
        {

            if(capsLockwlaczony)
                capsLockwlaczony = false;
            else
                capsLockwlaczony = true;
        }



        private void _backspacebtn_Click(object sender, RoutedEventArgs e)
        {
           string s = pisanietb.Text;

            if (s.Length > 1)
            {
                s = s.Substring(0, s.Length - 1);
            }
            else
            {
                s = "";
            }

            pisanietb.Text = s;
        }

    }
}