Merging FDF data to a PDF

To import XFDF into FDF, then merge data from FDF into PDF

// Import form field data from XFDF to FDF
FDFDoc fdf_doc(FDFDoc::CreateFromXFDF(xfdf_filename);
fdf_doc.Save(output_fdf_filename);

// Merge FDF data into PDF doc
PDFDoc doc(filename);
doc.FDFMerge(fdf_doc);

PDF Form fill and form data extraction
Full sample code which illustrates basic FDF merge/extract functionality and full support for FDF (Forms Data Format)