MainWindow.xaml

<Window x:Class="WpfApplication.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:WpfApplication"
        Title="MainWindow" Height="359" Width="794" xmlns:dxdo="http://schemas.devexpress.com/winfx/2008/xaml/docking">
    <Window.DataContext>
        <local:MainViewModel />
    </Window.DataContext>
    <Grid x:Name="mainGrid">
        
        <Grid.RowDefinitions>
            <RowDefinition Height="20"/>
            <RowDefinition Height="20"/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <Button Content="Pin Messages" Command="{Binding PinMessagesCommand}" Grid.Row="0"/>
        <Button Content="UnPin Messages" Command="{Binding UnpinMessagesCommand}" Grid.Row="1"/>
        <dxdo:DockLayoutManager Grid.Row="2" Name="dockLayoutManager1"  ItemsSource="{Binding ChildViews}">
            <dxdo:DockLayoutManager.LayoutRoot>
                <dxdo:LayoutGroup Caption="LayoutRoot" >
                    <dxdo:DocumentGroup x:Name="DocumentsGroup">
                    </dxdo:DocumentGroup>
                    <dxdo:LayoutGroup x:Name="DockPanels" Orientation="Vertical">
                    </dxdo:LayoutGroup>
                </dxdo:LayoutGroup>
            </dxdo:DockLayoutManager.LayoutRoot>
            <dxdo:DockLayoutManager.AutoHideGroups>
                <dxdo:AutoHideGroup DockType="Right" Name="auotHideGroup"/>
            </dxdo:DockLayoutManager.AutoHideGroups>
            

        </dxdo:DockLayoutManager>
    </Grid>
</Window>