How to fill forms like this using iText for .NET

Question

Trying to fill name and address on each boxes using

 cb.SetTextMatrix(x, y);// x and y positions .
 cb.ShowText("data");

But fails to do so .

the problem

Answer 1

The code you are using isn't entirely incorrect, but it has several flaws. For starters: you don't know the value of the x and y parameters, and that's kind of crucial if you want the text to be in the correct position.

Also: you are writing PDF syntax directly into the content stream. In your snippet, you forgot to create the text object (with cb.BeginText() and cb.EndText()). If you are new at PDF, you shouldn't try writing PDF syntax directly into the content stream unless you have a solid understanding of ISO-32000-1. Have you ever read ISO-32000-1? If not, then why are you using low-level operations? That doesn't make much sense, does it? There are helper classes such as ColumnText to add content at absolute positions.

Looking at the screen shot you shared, I see that some fields require "Comb" functionality. This functionality makes sure that each small box contains exactly one glyph (if you don't know what a glyph is, think of it as the visual representation of a character).

If you want to make it easy on yourself, you should test if the form is interactive first. Answer this question:

Does the form contain AcroFields?

If the answer is "Yes", fill out the form using the AcroFields object. You can find out which field names to use by following the instructions in the answer to this question: How do I enumerate all the fields in a PDF file in ITextSharp ?

If the answer is "No", open the file in Adobe Acrobat, and manually add fields. Define the fields as Comb fields so that each box contains each glyph. To get a nice-looking result, select a monospaced font such as Courier (using a proportional font will probably give you an uglier result). This operation adds AcroForm fields.

Once you have an interactive form with AcroFields (assuming you have defined them correctly), filling out the form is as easy as this in iText 5:

PdfReader reader = new PdfReader(template);
PdfStamper stamper = new PdfStamper(reader,
    new FileStream(newFile, FileMode.Create));
AcroFields form = stamper.AcroFields;         
form.SetField(key1, value1);      
form.SetField(key2, value2);      
form.SetField(key3, value3);
...
stamper.Close();

See How to create and fill out a PDF form

However, since you are new at all of this, I recommend that you use iText 7 as described in the jump-start tutorial:

PdfDocument pdf = new PdfDocument(new PdfReader(src), new PdfWriter(dest));
PdfAcroForm form = PdfAcroForm.GetAcroForm(pdf, true);
IDictionary<String, PdfFormField> fields = form.GetFormFields();
PdfFormField toSet;
fields.TryGetValue(key1, out toSet);
toSet.SetValue(value1);
fields.TryGetValue(key2, out toSet);
toSet.SetValue(value2);
...
pdf.Close();

If you want to remove the interactivity after filling out the form, you need to flatten the fields. This is also documented on the official web site.