>>Here's some code I'm using in production. There is an imports statement and iTextsharp.dll is included as a reference
>>This goes through every PDF form in a folder and returns a report of all the fields found. ( not their contents, the field names)
>>
>>I think this is the only line that uses iTextsharp in this routine
>>
>> pdffields = GetPDFFormFields(pdffile)
>>
>>
>>I have a version I'll be happy to post that produces a complete report of distinct field names found in all the PDFs in order to determine what datapoints need to be available.
>>
>>If you google itextsharp c# tutorial you should find lots of information on how to use iTextsharp to extract whatever you need from pdfs or to create pdfs on the fly or fill pdfs fields.
>>
>>There is also something called antlr I am using and I am now researching to see what I use it for and if it would help in what you're doing . I'll get back to you on that.
>>
>>Are you primarily interested in reading data from PDF forms that others have filled in or are you going to be filling out pdf forms from data ( I do mostly the latter )
>
>I am reading only. And, we have no idea about the field names. So, I need to get all the field names in a collection. Then, by deduction, we will be able to see what field we need to use. We have 10 sample PDF files. So, when I will extract the related value, I will be able to see if the proper field name was used.

Yes that is very much like the situation I had and this worked very well.

Here is the code to get a distinct list of all the fields for all the forms in the folder
(actually in this one I am iterating the business object that holds the metadata for the PDFs in the folder, but you get the idea )

    Public Sub Allfieldslist()

        Dim Allfieldlist As List(Of String) = New List(Of String)

        Me.CarriersBO1.SeekToPrimaryKey(Me.cboCarriers.SelectedValue)

        With Me.PdfFormsBO1

            Dim oldfiltstr As String = .Filter
            .Filter = String.Format("{0} = {1}", "icarrierskey", Me.CarriersBO1.ikey)

            For Each bo In Me.PdfFormsBO1.GetEnumerable()

                Dim _
                    FieldsArray As String() = _
                        Me.PdfFormsBO1.PDFFormFields.Split(New String() {ControlChars.NewLine, ",", ";"}, _
                                                           StringSplitOptions.RemoveEmptyEntries)

                For Each fld As String In FieldsArray
                    If Not Allfieldlist.Contains(fld) Then
                        Allfieldlist.Add(fld)
                    End If
                Next
            Next


            .Filter = oldfiltstr

        End With
        Dim myWriter As StreamWriter
        Dim myStream As FileStream
        Dim outfile As String = Path.Combine(Me.CarriersBO1.PDFFormPath, Me.CarriersBO1.Carrier & "fields.txt")

        myStream = New FileStream(outfile, FileMode.Create)
        myWriter = New StreamWriter(myStream)

        Allfieldlist.Sort()


        Dim field As String
        For Each field In Allfieldlist
            myWriter.Write(field.ToString)
            myWriter.WriteLine()
        Next

        myWriter.Close()
        myStream.Close()

        Process.Start(outfile)


    End Sub