c# - How to create pdfformfields using iTextSharp?

Question

I am using iTextSharp and CSharp for creating the pdf. I need to add formfields like checkbox, radiobutton and dropdown which can not be edited.

I used this..

FileStream pdffile = new FileStream(path + "/Pdf/tes.pdf",FileMode.Create);
PdfWriter writer = PdfWriter.GetInstance(doc, pdffile);
doc.Open(); 
Rectangle rect = new Rectangle(100, 100, 100, 100);
RadioCheckField checkbox = new RadioCheckField(writer, rect, "bhjabsdf", "on");
checkbox.CheckType = RadioCheckField.TYPE_CHECK;
PdfFormField field = checkbox.CheckField;
writer.AddAnnotation(field);
doc.Close();

But it's not working. I also read about PdfStamper. But I am creating a new pdf, not changing the existing one.So I don't know whether I can use PdfStamper?

Thanks..

Edit:

private void CreateRadioButton(PdfWriter writer, PdfContentByte cb,Font font)
    {
        Rectangle rect;
        PdfFormField field;
        PdfFormField radiogroup = PdfFormField.CreateRadioButton(writer, true);
        radiogroup.FieldName = "language";
        RadioCheckField radio;
        int x = 20;
        for (int i = 0; i < Petrol.Length; i++)
        {
            rect = new Rectangle(440 + i * x, 692, 450 + i * x, 682);
            radio = new RadioCheckField(writer, rect, null, LANGUAGES[i]);
            radio.BorderColor = GrayColor.GRAYBLACK;
            radio.BackgroundColor = BaseColor.WHITE;
            radio.CheckType = RadioCheckField.TYPE_CIRCLE; 

            if (Petrol[i] == "F")
                radio.Checked = true;
            field = radio.RadioField;
            //Here i am setting readonly..

            field.SetFieldFlags(PdfFormField.FF_READ_ONLY);
            radiogroup.AddKid(field);                
            ColumnText.ShowTextAligned(cb, Element.ALIGN_LEFT,
              new Phrase(Petrol[i], font), 451 + i * x, 684, 0);
            if (i >= 1) x = 25;
        }
        writer.AddAnnotation(radiogroup);
    }

Answer 1

You're creating a field 'the hard way'. There's a class named RadioCheckField that makes it much easier for you to create a field.

Please take a look at the book examples from Chapter 8. You can find C# versions of the examples here, for instance an example named Buttons.

checkbox = new RadioCheckField(writer, rect, LANGUAGES[i], "on");
checkbox.CheckType = RadioCheckField.TYPE_CHECK;
PdfFormField field = checkbox.CheckField;