How to access ScrollViewer

MarkdownScrollViewer extends FlowDocumentScrollViewer which has no properties to access ScrollViewer. To access ScrollViewer, We should walk a visual tree.

a viewclass containing MarkdownScrollViewer:

// MarkdownScrollViewer MdScrlViewer;

public ScrollViewer ScrollViewer
{
    get
    {
        DependencyObject obj = MdScrlViewer;

        do
        {
            if (VisualTreeHelper.GetChildrenCount(obj) > 0)
                obj = VisualTreeHelper.GetChild(obj as Visual, 0);
            else
                return null;
        }
        while (!(obj is ScrollViewer));

        return obj as ScrollViewer;
    }
}

Click here for sample projects. MainWindow.xaml and MainWindow.xaml.cs is the view containing MarkdownScrollViewer.