I have an app where the user is allowed to change the font name/size of a file completely.  I know all formatting is lost but this is what the users want.  The code I am using is

NRichTextView mmdv = new NRichTextView()
...
mmdv.Content.Selection.SelectAll();
mmdv.Content.Selection.SetFontSizeToSelectedInLines(24.0);
mmdv.Content.Selection.DeselectAll();

but that doesn't work.  I've also tried stepping through the Sections
for (int a = 0; a < mmdv.Content.Sections.Count; a++)
{
  mmdv.Content.Sections[a].FontName = "Cochin";
etc
}
Nothing works.  Obviously I've misunderstood something somewhere but can anyone throw light on it?
Neil