How to extract form data from existing PDF documents

The following code extracts AcroForm data from a file called "form.pdf" and creates a new file called "form.fdf"

c# sample:

    PDFOperation op = new PDFOperation("Form.pdf", "");
    op.ExportAcroFormData("form.fdf", DataFormat.XFDF, "Form.pdf");
    op.Close();