Q: I need to flatten annotations inside an existing PDF. The
flattening must include both text and graphical annotations. Can I
use PDFNet SDK to implement this feature?
A: You can use PDFNet SDK (www.pdftron.com/net) to flatten
annotations inside an existing PDF. As a starting point you may want
to take a look at the last code example in InteractiveForms sample
The utility method pdfdoc.FlattenAnnotations(true) will flatten all form fields
that have appearance streams. If the PDF document does not contain
appearance streams you may need to call
pdfdoc.RefreshFieldAppearances() before flattening.
Using PDFNet API you can also implement flattening for other
annotation types besides widgets (e.g. markup, notes). In this case
you would use annot.GetAppearanceStream() and ElementReader to read
elements from the annotation and ElementWriter to merge the graphical
elements with the underlying page.