Programmatically Complete PDF Form Fields using Visual Basic and the iTextSharp DLL

Imports System
Imports System.Collections
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Text
Imports System.Windows.Forms
Imports iTextSharp
Imports iTextSharp.text
Imports iTextSharp.text.pdf
Imports iTextSharp.text.xml
Imports System.IO


Public Class Form1


    ''' <summary>
    ''' Application main form Load event handler
    ''' </summary>
    ''' <param name="sender"></param>
    ''' <param name="e"></param>
    ''' <remarks></remarks>
    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        ' Load all field names from template PDF
        ListFieldNames()

        ' Fill the target PDF form with canned values
        FillForm()

    End Sub



    ''' <summary>
    ''' List all of the form fields into a textbox.  The
    ''' form fields identified can be used to map each of the
    ''' fields in a PDF.
    ''' </summary>
    Private Sub ListFieldNames()

        Dim pdfTemplate As String = "c:\Temp\PDF\fw4.pdf"

        ' title the form
        Me.Text += " - " + PdfTemplate

        ' create a new PDF reader based on the PDF template document
        Dim pdfReader As PdfReader = New PdfReader(pdfTemplate)

        ' create and populate a string builder with each of the 
        ' field names available in the subject PDF
        Dim sb As New StringBuilder()

        Dim de As New DictionaryEntry
        For Each de In pdfReader.AcroFields.Fields
            sb.Append(de.Key.ToString() + Environment.NewLine)
        Next

        ' Write the string builder's content to the form's textbox
        textBox1.Text = sb.ToString()
        textBox1.SelectionStart = 0

    End Sub




    Private Sub FillForm()

        Dim pdfTemplate As String = "c:\Temp\PDF\fw4.pdf"
        Dim newFile As String = "c:\Temp\PDF\Final_fw4.pdf"

        Dim pdfReader As New PdfReader(pdfTemplate)
        Dim pdfStamper As New PdfStamper(pdfReader, New FileStream( _
                    newFile, FileMode.Create))

        Dim pdfFormFields As AcroFields = pdfStamper.AcroFields

        ' set form pdfFormFields

        ' The first worksheet and W-4 form
        pdfFormFields.SetField("f1_01(0)", "1")
        pdfFormFields.SetField("f1_02(0)", "1")
        pdfFormFields.SetField("f1_03(0)", "1")
        pdfFormFields.SetField("f1_04(0)", "8")
        pdfFormFields.SetField("f1_05(0)", "0")
        pdfFormFields.SetField("f1_06(0)", "1")
        pdfFormFields.SetField("f1_07(0)", "16")
        pdfFormFields.SetField("f1_08(0)", "28")
        pdfFormFields.SetField("f1_09(0)", "Franklin A.")
        pdfFormFields.SetField("f1_10(0)", "Benefield")
        pdfFormFields.SetField("f1_11(0)", "532")
        pdfFormFields.SetField("f1_12(0)", "12")
        pdfFormFields.SetField("f1_13(0)", "1234")

        ' The form's checkboxes
        pdfFormFields.SetField("c1_01(0)", "0")
        pdfFormFields.SetField("c1_02(0)", "Yes")
        pdfFormFields.SetField("c1_03(0)", "0")
        pdfFormFields.SetField("c1_04(0)", "Yes")

        ' The rest of the form pdfFormFields
        pdfFormFields.SetField("f1_14(0)", "100 North Cujo Street")
        pdfFormFields.SetField("f1_15(0)", "Nome, AK  67201")
        pdfFormFields.SetField("f1_16(0)", "9")
        pdfFormFields.SetField("f1_17(0)", "10")
        pdfFormFields.SetField("f1_18(0)", "11")
        pdfFormFields.SetField("f1_19(0)", "Walmart, Nome, AK")
        pdfFormFields.SetField("f1_20(0)", "WAL666")
        pdfFormFields.SetField("f1_21(0)", "AB")
        pdfFormFields.SetField("f1_22(0)", "4321")

        ' Second Worksheets pdfFormFields
        ' In order to map the fields, I just pass them a sequential
        ' number to mark them once I know which field is which, I 
        ' can pass the appropriate value
        pdfFormFields.SetField("f2_01(0)", "1")
        pdfFormFields.SetField("f2_02(0)", "2")
        pdfFormFields.SetField("f2_03(0)", "3")
        pdfFormFields.SetField("f2_04(0)", "4")
        pdfFormFields.SetField("f2_05(0)", "5")
        pdfFormFields.SetField("f2_06(0)", "6")
        pdfFormFields.SetField("f2_07(0)", "7")
        pdfFormFields.SetField("f2_08(0)", "8")
        pdfFormFields.SetField("f2_09(0)", "9")
        pdfFormFields.SetField("f2_10(0)", "10")
        pdfFormFields.SetField("f2_11(0)", "11")
        pdfFormFields.SetField("f2_12(0)", "12")
        pdfFormFields.SetField("f2_13(0)", "13")
        pdfFormFields.SetField("f2_14(0)", "14")
        pdfFormFields.SetField("f2_15(0)", "15")
        pdfFormFields.SetField("f2_16(0)", "16")
        pdfFormFields.SetField("f2_17(0)", "17")
        pdfFormFields.SetField("f2_18(0)", "18")
        pdfFormFields.SetField("f2_19(0)", "19")

        ' report by reading values from completed PDF
        Dim sTmp As String = "W-4 Completed for " + pdfFormFields.GetField("f1_09(0)") + " " + _
        pdfFormFields.GetField("f1_10(0)")
        MessageBox.Show(sTmp, "Finished")

        ' flatten the form to remove editting options, set it to false
        ' to leave the form open to subsequent manual edits
        pdfStamper.FormFlattening = True

        ' close the pdf
        pdfStamper.Close()

    End Sub


End Class