MainWindow.xaml

<Window x:Class="DXRichEdit_SpellCheckMenu.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
        xmlns:dxb="http://schemas.devexpress.com/winfx/2008/xaml/bars"
        xmlns:dxe="http://schemas.devexpress.com/winfx/2008/xaml/editors"
        xmlns:dxre="http://schemas.devexpress.com/winfx/2008/xaml/richedit"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <ResourceDictionary>
            <dxre:RichEditUICommand x:Key="commands" />
        </ResourceDictionary>
    </Window.Resources>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="29" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <dxb:BarManager Name="barManager1" Grid.Row="1">
            <dxre:RichEditControl x:Name="richEdit" VerticalAlignment="Stretch" BarManager="{Binding ElementName=barManager1, Mode=OneTime}" ShowBorder="False"/>
        </dxb:BarManager>
        <Button Content="Russian Spell Check" Height="23" HorizontalAlignment="Left" Name="button1" VerticalAlignment="Top" Width="153" Click="button1_Click" />
    </Grid>
</Window>