![]() | Forms Data Format |
This topic contains the following sections:
FDF is a file format for representing form data and annotations that are contained in a PDF form. It is a simplified file format based on the Adobe PDF document format. It allows creating form data, submitting structured form data to a server, receiving a response from the server and populating the form (in a PDF document) with the inquiry result.
Simply put, FDF is a tool to manipulate forms used in PDF documents.
To export form data to a FdfDocument, please use function PdfInteractiveFormsExportToFdf. This function exports data from a form to the FDF document. Basically, this function takes a PDF document with a form, fetches all data from this form and exports them to the FDF document.
To import form data from a FDF document, please use function PdfInteractiveFormsImportFromFdf. This function does the opposite: it imports the data from the specified FDF document to the PDF object.
using (var doc = PdfDocument.Load("sample.pdf", new PdfForms())) { doc.FormFill.ForceToKillFocus(); using (var fdf = doc.FormFill.InterForm.ExportToFdf(null)) { string content = fdf.Content; var data = System.Text.Encoding.UTF8.GetBytes(content); _memStream = new MemoryStream(data); } }
using (var doc = PdfDocument.Load("sample.pdf", new PdfForms())) { using (var fdf = FdfDocument.Load(_memStream)) { doc.FormFill.InterForm.ImportFromFdf(fdf); } }