How to retrieve user selected indices from listbox on PDF using itextsharp?

Question

I have listbox on PDF.

User will select multiple options from listbox.

I need to upload PDF to database.

I am unable to retrieve selected indices from listbox using iTextSharp? I tried with

SetListSelection("listbox", PreviousExport.ToArray) but no luck.

How to retrieve user selected indices from listbox on PDF using itextsharp?

Code from comments:

I am using below code to load listbox .. This is from database

form.SetListOption("ddlNoteStatus", strbuilderExport.ToArray, strbuilderDisplay.ToArray)
stamper.AcroFields.SetField("ddlNoteStatus", "3")

I am able to retrieve other fields from pdf which are not of listbox with below code. But if I use same code for list box only last value selected from list box shows but not all values selected by user

stamper.AcroFields.GetField("txtDateFollow")

Answer 1

Instead of GetField you want to use GetListSelection. To be safe, you might want to always call GetFieldType to determine the type of field that you're looking at. The below code shows this off:

using (var r = new PdfReader(testFile)) {
    var acro = r.AcroFields;
    if(acro.GetFieldType("countries") == AcroFields.FIELD_TYPE_LIST ){
        Console.WriteLine(String.Join(",", acro.GetListSelection("countries").ToArray()));
    }
}

I tested the above code against a PDF that I created using the below code:

var testFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "test.pdf");

using (var fs = new FileStream(testFile, FileMode.Create, FileAccess.Write, FileShare.None)) {
    using (var doc = new Document()) {
        using (var writer = PdfWriter.GetInstance(doc, fs)) {
            doc.Open();

            doc.Add(new Paragraph("Hello World"));

            var dd = new iTextSharp.text.pdf.TextField(writer, new iTextSharp.text.Rectangle(50, 500, 200, 550), "countries");
            dd.Choices = new string[] { "United States", "Canada", "France" };
            dd.ChoiceExports = new string[] { "US", "CA", "FR" };
            dd.Options = dd.Options | TextField.MULTISELECT;
            dd.ChoiceSelections = new List<int>(new int[] { 0, 2 });
            writer.AddAnnotation(dd.GetListField());
            doc.Close();
        }
    }
}