property FormFill;
Interface that lets your application supply forms-related callbacks (Beep, Invalidate, OutputDocFile, etc.).
Assign a custom implementation to override the default no-op handlers.
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.Active를 확인하세요. open document가 필요하면 그렇지 않을 때 EPdfError가 발생합니다SaveToFile를 호출하세요
if Pdf1.Active then
Pdf1.FormFill;