property CurrentCharIndex: Integer;
Read-only zero-based character index under the current mouse cursor (or last hit-tested point).
Lo usa el resaltador de búsqueda integrado; devuelve -1 cuando el cursor no está sobre texto
All TPdfView display properties trigger a repaint when assigned; you can change several in sequence without flicker because the redraw is coalesced into a single invalidation.
Active := True.PdfView1.Pdf at runtime, re-apply any view-only settings — the new TPdf has its own state.
begin
PdfView1.CurrentCharIndex := {value};
PdfView1.Active := True;
end;