QuickLook/QuickLook.Plugin/QuickLook.Plugin.TextViewer/TextViewerPanel.xaml

<UserControl x:Class="QuickLook.Plugin.TextViewer.TextViewerPanel"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:avalonEdit="http://icsharpcode.net/sharpdevelop/avalonedit"
             xmlns:local="clr-namespace:QuickLook.Plugin.TextViewer"
             mc:Ignorable="d"
             d:DesignHeight="317.974"
             d:DesignWidth="448.79"
             UseLayoutRounding="True">
    <Grid>
        <avalonEdit:TextEditor x:Name="viewer" Background="#00FFFFFF" FontFamily="Consolas" FontSize="14"
                               ShowLineNumbers="True"
                               WordWrap="True" IsReadOnly="True" />
    </Grid>
</UserControl>