I've looked at other posts, but i cant seem to find something that works. I have a custom control WPF RichTextBox and would like to obtain the XAML from this control.

I have tried the following

    //rt is the name of this particular custom richtextbox
    TextRange range = new TextRange(rt.Document.ContentStart, rt.Document.ContentEnd);
    MemoryStream stream = new MemoryStream();
    range.Save(stream, DataFormats.Xaml);
    string xamlText = Encoding.UTF8.GetString(stream.ToArray());
    return xamlText;

but this doesnt seem to work :s I can access the rt.Document.Content start etc but it seems to crash there "Object Reference not set to instance of an object".

I am using the richtextbox directly from the .xaml.cs so it should be initiated and so on :s.

Any Ideas or other ways to get the XAML from a richtextbox pls? (i'm requiring the XAML cos i actually want to get the HTML.. if theres some other direct manner perhaps?)