How to read PDF form data using iTextSharp?

Question

I am trying to find out if it is possible to read PDF Form data (Forms filled in and saved with the form) using iTextSharp. How can I do this?

Answer 1

The PDF name is "report.pdf"..

The data field to be read into TextBox1 is "TextField25" in the PDF..

        Dim pdf As String = "report.pdf"
        Dim reader As New PdfReader(pdf)
        Dim fields As AcroFields = reader.AcroFields
        TextBox1.Text = fields.GetField("TextField25")

Important Note: This can be used ONLY IF the PDF is not flattened (means the fields should be editable) while it was created using iTextSharp..

i.e.

       pdfStamper.FormFlattening = False

This is very simple.. And it works like a charm.. :)

Answer 2

This worked for me! Note the parameters when defining stamper! '\0', true

            string TempFilename = Path.GetTempFileName();

            PdfReader pdfReader = new PdfReader(FileName);
            //PdfStamper stamper = new PdfStamper(pdfReader, new FileStream(TempFilename, FileMode.Create));
            PdfStamper stamper = new PdfStamper(pdfReader, new FileStream(TempFilename, FileMode.Create), '\0', true);

            AcroFields fields = stamper.AcroFields;
            AcroFields pdfFormFields = pdfReader.AcroFields;

            foreach (KeyValuePair<string, AcroFields.Item> kvp in fields.Fields)
            {
                string FieldValue = GetXMLNode(XMLFile, kvp.Key);
                if (FieldValue != "")
                {
                    fields.SetField(kvp.Key, FieldValue);
                }
            }

            stamper.FormFlattening = false;
            stamper.Close();
            pdfReader.Close()

Answer 3

Maybe the iTextSharp library has changed recently but I wasn't able to get the accepted answer to work. Here is my solution:

var pdf_filename = "pdf2read.pdf";
using (var reader = new PdfReader(pdf_filename))
{
    var fields = reader.AcroFields.Fields;

    foreach (var key in fields.Keys)
    {
        var value = reader.AcroFields.GetField(key);
        Console.WriteLine(key + " : " + value);
    }
}

A very subtle difference, due to reader.AcroFields.Fields returning an IDictionary instead of just an AcroFields object.

Answer 4

If you are using Powershell, the discovery code for fields is:

    Add-Type -Path C:\Users\Micah\Desktop\PDF_Test\itextsharp.dll
    $MyPDF = "C:\Users\Micah\Desktop\PDF_Test\something_important.pdf"
    $PDFDoc = New-Object iTextSharp.text.pdf.pdfreader -ArgumentList $MyPDF
    $PDFDoc.AcroFields.Fields

That code will give you the names of all the fields on the PDF Document, "something_important.pdf".

This is how you access each field once you know the name of the field:

    $PDFDoc.AcroFields.GetField("Name of the field here")

Answer 5

You would have to find out the field names in the PDF form. Get the fields and then read their value.

string pdfTemplate = "my.pdf";
PdfReader pdfReader = new PdfReader(pdfTemplate);
AcroFields fields = pdfReader.AcroFields.Fields;
string val = fields.GetField("fieldname");

Obviously in the code above, field name is the name of the PDF form field and the GetField method returns a string representation of that value. Here is an article with example code that you could probably use. It shows how you can both read and write form fields using iTextSharp.