我如何重置ICSharpCode.AvalonEdit语法高亮显示

我正在托管ICSharpCode AvalonEdit源代码编辑WPF控件到我的Windows Forms c#应用程序。我知道下面的代码加载了一个语法高亮显示定义:

ICSharpCode.AvalonEdit.TextEditor MyEditor = new ICSharpCode.AvalonEdit.TextEditor();
MyEditor.ShowLineNumbers = true;
Stream xshd_stream = File.OpenRead("C:''Syntax Highlighting''php.xsdh");
XmlTextReader xshd_reader = new XmlTextReader(xshd_stream);
// Apply the new syntax highlighting definition.
MyEditor.SyntaxHighlighting = ICSharpCode.AvalonEdit.Highlighting.Xshd.HighlightingLoader.Load(
    xshd_reader, ICSharpCode.AvalonEdit.Highlighting.HighlightingManager.Instance
);
xshd_reader.Close();
xshd_stream.Close();

但是，如果在我已经设置了语法突出显示定义之后，我不想要任何语法突出显示，而只想将其显示为纯文本，该怎么办?如何在AvalonEdit控件中禁用语法高亮显示?

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="*"/>
        <RowDefinition Height="Auto"/>
    </Grid.RowDefinitions>
    <avalonEdit:TextEditor SyntaxHighlighting="C#" x:Name="TextEditor">
        public class Foo
        {
        }
    </avalonEdit:TextEditor>
    <Button Grid.Row="1" Content="Reset syntax highlighting" Click="Button_Click" />
</Grid>

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        TextEditor.SyntaxHighlighting = null; // highlighting disappears
    }