MainWindow.xaml

<Window x:Class="DXRichEditSyntaxExample.MainWindow"
        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:DXRichEditSyntaxExample"
        xmlns:dxre="http://schemas.devexpress.com/winfx/2008/xaml/richedit"
        mc:Ignorable="d"
        Title="T-SQL Syntax" Height="450" Width="800">
    <Grid>
        <dxre:RichEditControl x:Name="richEditControl1" ActiveViewType="Draft">
            <dxre:RichEditControl.SearchOptions>
                <dxre:DXRichEditDocumentSearchOptions RegExResultMaxGuaranteedLength="500"/>
            </dxre:RichEditControl.SearchOptions>
        </dxre:RichEditControl>
    </Grid>
</Window>