procedure SetFormFieldFlagsAt(X, Y: Single; const Flags: TPdfFormFieldFlags);
Sets the Flags bit field on the form field at the given coordinates.
Use to toggle ReadOnly, Required, Multiline, Password, etc. without re-acquiring the index.
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 bevor seitenbezogene Operationen aufgerufen werden; Methoden, die ein geöffnetes Dokument erfordern, lösen EPdfError otherwise.SaveToFile to persist.
if Pdf1.Active then
Pdf1.SetFormFieldFlagsAt;