To add a hyperlink or intra-document link annotation to a PDF Document page.

PDFDoc doc(filename);
Page page = doc.GetPage(1);

// Create a hyperlink
Annots::Link hyperlink = Annots::Link::Create(doc, Rect(85, 570, 503, 524), Action::CreateURI(doc, "http://www.pdftron.com"));
hyperlink.RefreshAppearance();
page.AnnotPushBack(hyperlink);

// Create an intra-document link
Action goto_page_3 = Action::CreateGoto(Destination::CreateFitH(doc.GetPage(3), 0));
Annots::Link link = Annots::Link::Create(doc, Rect(85, 458, 503, 502), goto_page_3);
link.RefreshAppearance();
page.AnnotPushBack(link);

Add or edit PDF annotations sample
Full code sample which shows how to add or edit PDF annotations (e.g. hyperlink, intra-document link, stamp, rubber stamp, file attachment, sound, text, free-text, line, circle, square, polygon, polyline, highlight, squiggly, caret, and ink).