KuznechikManager.xaml

<Window x:Class="InformationSecurity.KuznechikManager"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:InformationSecurity"
        mc:Ignorable="d"
        Title="Лабка ИБ — Шифрование Кузнечиком" Height="450" Width="800">
    <Grid Margin="10">
        <Grid.RowDefinitions>
            <RowDefinition Height="auto"/>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <StackPanel
            Grid.Row="0"
            Orientation="Horizontal"
            HorizontalAlignment="Stretch"
            >
            <Button
                x:Name="btnSave"
                VerticalAlignment="Top"
                HorizontalAlignment="Stretch"
                Content="Сохранить изменения таблицы"
                Click="btnSave_Click"
                />
            <Button
                x:Name="btnReturn"
                VerticalAlignment="Top"
                HorizontalAlignment="Stretch"
                Margin="5,0,0,0"
                Content="Выйти"
                Click="btnReturn_Click"
                />
        </StackPanel>
        <DataGrid
            Grid.Row="1"
            VerticalScrollBarVisibility="Auto"
            VerticalAlignment="Top"
            AutoGenerateColumns="False"
            IsTextSearchEnabled="True"
            CanUserDeleteRows="False"
            CanUserAddRows="False"
            CanUserSortColumns="True"
            x:Name="dgData" 
            >
            <DataGrid.Columns>
                <DataGridTextColumn x:Name="clmLogin" Binding="{Binding user,       UpdateSourceTrigger=PropertyChanged}" Header="Логин"/>
                <DataGridTextColumn IsReadOnly="True" Binding="{Binding first_key,  UpdateSourceTrigger=PropertyChanged}" Header="1ый ключ"/>
                <DataGridTextColumn IsReadOnly="True" Binding="{Binding second_key, UpdateSourceTrigger=PropertyChanged}" Header="2ой ключ"/>
                <DataGridTextColumn IsReadOnly="True" Binding="{Binding message,    UpdateSourceTrigger=PropertyChanged}" Header="Сообщение"/>
                <DataGridTextColumn IsReadOnly="True" Binding="{Binding cipher,     UpdateSourceTrigger=PropertyChanged}" Header="Шифр"/>
            </DataGrid.Columns>
        </DataGrid>
        <StackPanel
            Grid.Row="2"
            VerticalAlignment="Bottom"
            >
            <StackPanel
                Orientation="Horizontal"
                HorizontalAlignment="Stretch" >
                <Button 
                    Content="Шифровать"
                    x:Name="btnCipher"
                    Click="btnCipher_Click" 
                    />
                <Button 
                    Content="Дешифровать" 
                    Margin="5,0,0,0"
                    x:Name="btnDecipher"
                    Click="btnDecipher_Click" 
                    />
                <Button 
                    Content="Сохранить данные в таблицу"
                    Margin="5,0,0,0"
                    x:Name="btnSaveToTable"
                    Click="btnSaveToTable_Click" 
                    />
                <Button
                    Margin="5,0,0,0"
                    Content="Указать все ключи"
                    x:Name="btnSetAllKeys"
                    Click="btnSetAllKeys_Click"
                    />
            </StackPanel>
            <TextBox 
                x:Name="txtKey1"
                Text="1-ый ключ"
                ToolTip="1-ый ключ"
                GotFocus="TextBox_GotFocus"
                LostFocus="TextBox_LostFocus"
                />
            <TextBox 
                x:Name="txtKey2"
                Text="2-ой ключ"
                ToolTip="2-ой ключ"
                GotFocus="TextBox_GotFocus"
                LostFocus="TextBox_LostFocus"
                />
            <ScrollViewer CanContentScroll="True" Height="60">
                <TextBox 
                    x:Name="txtInput"
                    VerticalAlignment="Stretch"
                    TextWrapping="Wrap"
                    Text="Текст"
                    ToolTip="Текст"
                    GotFocus="TextBox_GotFocus"
                    LostFocus="TextBox_LostFocus"
                    />
            </ScrollViewer>
            <ScrollViewer CanContentScroll="True" Height="60">
                <TextBox 
                    x:Name="txtOutput"
                    VerticalAlignment="Stretch"
                    TextWrapping="Wrap"
                    Text="Шифр"
                    ToolTip="Шифр"
                    GotFocus="TextBox_GotFocus"
                    LostFocus="TextBox_LostFocus"
                    />
            </ScrollViewer>
        </StackPanel>
    </Grid>
</Window>