Working with FDF and XFDF Files

Spire.PDF allows importing FDF, XFDF files to PDF forms as well as exporting PDF forms data to FDF, XFDF files.

The below code examples illustrate how to implement the above features using Spire.PDF.

Importing FDF/ XFDF to PDF

To import FDF/XFDF file to PDF, we can use the ImportData method in the PdfFormWidget class:

//Load the PDF document
PdfDocument document = new PdfDocument("Import.pdf");

//Load the existing forms 
PdfFormWidget loadedForm = document.Form as PdfFormWidget;

//Import FDF to PDF
loadedForm.ImportData("ImportFDF.fdf", DataFormat.Fdf);

//Import XFDF to PDF
//loadedForm.ImportData("ImportXFDF.xfdf", DataFormat.XFdf);

//Save the document
document.SaveToFile("Output.pdf");

//Close the document
document.Close();

Exporting PDF Forms Data to FDF/XFDF

To export PDF forms data to FDF/XFDF file, we can use the ExportData method in the PdfFormWidget class:

// Load the PDF document
PdfDocument document = new PdfDocument("Export.pdf");

//Load the existing forms 
PdfFormWidget loadedForm = document.Form as PdfFormWidget;

//Export the first form to FDF
PdfField field = loadedForm.FieldsWidget.List[0] as PdfField;
loadedForm.ExportData("ExportFDF.fdf", DataFormat.Fdf, field.Name);

//Export the first form to XFDF
//loadedForm.ExportData("ExportXFDF.xfdf", DataFormat.XFdf, field.Name);

//Close the document
document.Close();