function Find;
Searches for Pattern starting from PageNum (or the current page if -1) and returns the global character index of the first match.
Returns -1 if not found. After a match, call Find with the next start index for incremental search, or use FindNext on TPdfView for an interactive UI.
Wraps the corresponding PDFium API and exposes it as a TPdf instance member so consumers do not have to manage FPDF_DOCUMENT handles directly.
Pdf1.Active before calling page-scoped operations; methods that require an open document raise EPdfError otherwise.SaveAs to persist.
if Pdf1.Active then
Pdf1.Find;