Field combo = doc.FieldCreate("my_combo", Field.Type.e_choice);combo.SetFlag(Field.Flag.e_combo, true);Obj options_array = combo.GetSDFObj().PutArray("Opt");// Add options...options_array.PushBackString("Item5");options_array.PushBackString("Item6");// Now create visual representation of field and add to pagepdftron.PDF.Annots.Widget combo_widget = pdftron.PDF.Annots.Widget.Create(sdfdoc, new Rect(50, 550, 350, 600), combo);page.PushBack(combo_widget);