如何将Home键/End键传播到WPF ScrollViewer中的UWP RichEditBox？

private void RichEditBox_KeyDown(object sender, KeyRoutedEventArgs e)
{
    if (e.Key == Windows.System.VirtualKey.Home)
    {
        // 寻找ScrollViewer
        ScrollViewer scrollViewer = FindScrollViewer(RichEditBox);

        if (scrollViewer != null)
        {
            // 滚动到开头
            scrollViewer.ChangeView(null, 0, null);
            e.Handled = true;
        }
    }
    else if (e.Key == Windows.System.VirtualKey.End)
    {
        // 寻找ScrollViewer
        ScrollViewer scrollViewer = FindScrollViewer(RichEditBox);

        if (scrollViewer != null)
        {
            // 滚动到结尾
            scrollViewer.ChangeView(null, scrollViewer.ExtentHeight, null);
            e.Handled = true;
        }
    }
}

private ScrollViewer FindScrollViewer(DependencyObject dependencyObject)
{
    ScrollViewer scrollViewer = dependencyObject as ScrollViewer;

    if (scrollViewer != null)
    {
        return scrollViewer;
    }

    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(dependencyObject); i++)
    {
        var child = VisualTreeHelper.GetChild(dependencyObject, i);
        var result = FindScrollViewer(child);

        if (result != null)
        {
            return result;
        }
    }

    return null;
}