MainWindow.xaml

<Window x:Class="ValidateEditingFields_MVVM.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:ValidateEditingFields_MVVM"
        xmlns:dxp="http://schemas.devexpress.com/winfx/2008/xaml/printing"
        xmlns:dxmvvm="http://schemas.devexpress.com/winfx/2008/xaml/mvvm"
        Title="MainWindow" Height="450" Width="800">
    <Window.DataContext>
        <local:ViewModel />
    </Window.DataContext>
    <Grid>
        <dxp:DocumentPreviewControl RequestDocumentCreation="True"
                                    DocumentSource="{Binding Report}"
                                    HighlightEditingFields="True">
            <dxmvvm:Interaction.Behaviors>
                <dxmvvm:EventToCommand Event="{x:Static dxp:DocumentPreviewControl.ShowingEditingFieldEditorEvent}"
                                       PassEventArgsToCommand="True"
                                       Command="{Binding OnShowingEditingFieldEditorCommand}" />
                <dxmvvm:EventToCommand Event="{x:Static dxp:DocumentPreviewControl.ValidateEditingFieldEvent}"
                                       PassEventArgsToCommand="True"
                                       Command="{Binding OnValidateEditingFieldCommand}" />
            </dxmvvm:Interaction.Behaviors>
        </dxp:DocumentPreviewControl>
    </Grid>
</Window>