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C# itextsharp working with letterhead

i have to merge two pdf files, one is the letterhead (source.pdf) an the other is a code generated pdf page (overlay.pdf). the letterhead can be a scanned or a digital copy. i used the code i found at here: https://social.msdn.microsoft.com/Forums/vstudio/en-US/e78ccbbf-3d00-4612-b342-269eb0075982/make-a-pdf-as-a-background-of-another-pdf?forum=csharpgeneral
. My problem is that the text from the overlay.pdf not showing up if the letterhead is scanned, when the letterhead is an digital copy etc. from Photsop it works! BUT the text is there in the output.pdf i can select it.
output.pdf with invisible text
i hope anyone has an idea. thank you

I'm a Java developer, so I am not familiar with all the details of C#. Nevertheless I'm going to try to write some C#. If that code doesn't work immediately, please treat it as if it were pseudo-code. The principles are correct; the syntax may contain errors.
// Actual content
PdfReader overlay = new PdfReader("overlay.pdf");
int n = overlay.NumberOfPages;
PdfStamper stamper = new PdfStamper(overlay,
new FileStream("result.pdf", FileMode.Create);
// Company stationery (letter head)
PdfReader stationery = new PdfReader("source.pdf");
PdfImportedPage page = stamper.GetImportedPage(stationery, 1);
// Add stationery page to each page of real content
PdfContentByte background;
for (int i = 1; i <= n; i++) {
background = stamper.GetUnderContent(i);
background.AddTemplate(page, 0, 0);
}
// Close the stamper
stamper.Close();
As I explained in my comment, there is no need to use PdfWriter. You just take the existing PDF with the real content, and you add the single-page PDF with the letterhead and you add it to the background.
Update
If your overlay.pdf is opaque, it is only normal that you won't see source.pdf as that content will be covered. In that case, you might consider using transparency:
// Actual content
PdfReader overlay = new PdfReader("overlay.pdf");
int n = overlay.NumberOfPages;
PdfStamper stamper = new PdfStamper(overlay,
new FileStream("result.pdf", FileMode.Create);
// Company stationery (letter head)
PdfReader stationery = new PdfReader("source.pdf");
PdfImportedPage page = stamper.GetImportedPage(stationery, 1);
// Add stationery page to each page of real content
PdfContentByte foreground;
PdfGState state = new PdfGState();
state.FillOpacity = 0.6f;
for (int i = 1; i <= n; i++) {
foreground = stamper.GetOverContent(i);
foreground..SaveState();
foreground.SetGState(state);
foreground.AddTemplate(page, 0, 0);
foreground.RestoreState();
}
// Close the stamper
stamper.Close();
This may not be the optimal result. You can try changing the 0.6 fill opacity, but it's the best result you'll get if crazy people give you opaque letter-head PDFs (that's not done; people who do this are totally unprofessional).

PDF generated with iTextSharp always prompts to save changes when closing. And has missing pages when viewed with non-Acrobat PDF readers

I've recently used iTextSharp to create a PDF by importing the 20 pages from an existing PDF and then adding a dynamically generated link to the bottom of the last page. It works fine... kind of. Viewing the generated PDF in Acrobat Reader on a windows PC displays everything as expected although when closing the document it always asks "Do you want to save changes?". Viewing the generated PDF on a Surface Pro with PDF Reader displays the document without the first and last pages. Apparently on a mobile device using Polaris Office the first and last pages are also missing.
I'm wondering if when the new PDF is generated it's not getting closed off quite properly and that's why it asks "Do you want to save changes?" when closing it. And maybe that's also why it doesn't display correctly in some PDF reader apps.
Here's the code:
using (var reader = new PdfReader(HostingEnvironment.MapPath("~/app/pdf/OriginalDoc.pdf")))
{
using (
var fileStream =
new FileStream(
HostingEnvironment.MapPath("~/documents/attachments/DocWithLink_" + id + ".pdf"),
FileMode.Create, FileAccess.Write))
{
var document = new Document(reader.GetPageSizeWithRotation(1));
var writer = PdfWriter.GetInstance(document, fileStream);
using (PdfStamper stamper = new PdfStamper(reader, fileStream))
{
var baseFont = BaseFont.CreateFont(BaseFont.HELVETICA_BOLD, BaseFont.CP1252,
BaseFont.NOT_EMBEDDED);
Font linkFont = FontFactory.GetFont("Arial", 12, Font.UNDERLINE, BaseColor.BLUE);
document.Open();
for (var i = 1; i <= reader.NumberOfPages; i++)
{
document.NewPage();
var importedPage = writer.GetImportedPage(reader, i);
// Copy page of original document to new document.
var contentByte = writer.DirectContent;
contentByte.AddTemplate(importedPage, 0, 0);
if (i == reader.NumberOfPages) // It's the last page so add link.
{
PdfContentByte cb = stamper.GetOverContent(i);
//Create a ColumnText object
var ct = new ColumnText(cb);
//Set the rectangle to write to
ct.SetSimpleColumn(100, 30, 500, 90, 0, PdfContentByte.ALIGN_LEFT);
//Add some text and make it blue so that it looks like a hyperlink
var c = new Chunk("Click here!", linkFont);
var congrats = new Paragraph("Congratulations on reading the eBook! ");
congrats.Alignment = PdfContentByte.ALIGN_LEFT;
c.SetAnchor("http://www.domain.com/pdf/response/" + encryptedId);
//Add the chunk to the ColumnText
congrats.Add(c);
ct.AddElement(congrats);
//Tell the system to process the above commands
ct.Go();
}
}
}
}
}
I've looked at these posts with similar issues but none seem to quite provide the answer I need:
iTextSharp-generated PDFs cause save dialog when closing
Using iTextSharp to write data to PDF works great, but Acrobat Reader asks 'Do you want to save changes' when closing file
(Or they refer to memory streams instead of writing to disk etc)
My question is, how do I modify the above so that when closing the generated PDF in Acrobat Reader there's no "Do you want to save changes?" prompt. The answer to that may solve the problems with missing pages on Surface Pro etc but if you know anything else about what might be causing that I'd like to hear about it.
Any suggestions would be very welcome! Thanks!

At first glance (and without much coffee yet) it appears that you're using a PdfReader in three different contexts, as a source to a PdfStamper, as a source for Document and as for a source for importing. So you are essentially importing a document into itself that you're also writing to.
To give you a quick overview, the following code will essentially clone the contents of source.pdf into dest.pdf:
using (var reader = new PdfReader("source.pdf")){
using (var fileStream = new FileStream("dest.pdf", FileMode.Create, FileAccess.Write)){
using (PdfStamper stamper = new PdfStamper(reader, fileStream)){
}
}
}
Since that does all of the cloning for you you don't need to import pages or anything.
Then, if the only thing that you want to do is add some text to the last page, you can just use the above and ask the PdfStamper for a PdfContentByte using GetOverContent() and telling it what page number you're interested. Then you can just use the rest of your ColumnText logic.
using (var reader = new PdfReader("Source.Pdf")) {
using (var fileStream = new FileStream("Dest.Pdf"), FileMode.Create, FileAccess.Write) {
using (PdfStamper stamper = new PdfStamper(reader, fileStream)) {
//Get a PdfContentByte object
var cb = stamper.GetOverContent(reader.NumberOfPages);
//Create a ColumnText object
var ct = new ColumnText(cb);
//Set the rectangle to write to
ct.SetSimpleColumn(100, 30, 500, 90, 0, PdfContentByte.ALIGN_LEFT);
//Add some text and make it blue so that it looks like a hyperlink
var c = new Chunk("Click here!", linkFont);
var congrats = new Paragraph("Congratulations on reading the eBook! ");
congrats.Alignment = PdfContentByte.ALIGN_LEFT;
c.SetAnchor("http://www.domain.com/pdf/response/" + encryptedId);
//Add the chunk to the ColumnText
congrats.Add(c);
ct.AddElement(congrats);
//Tell the system to process the above commands
ct.Go();
}
}
}

ITextSharp PDFTemplate FormFlattening removes filled data

I am porting an existing app from Java to C#. The original app used the IText library to fill PDF form templates and save them as new PDF's. My C# code (example) below:
string templateFilename = #"C:\Templates\test.pdf";
string outputFilename = #"C:\Output\demo.pdf";
using (var existingFileStream = new FileStream(templateFilename, FileMode.Open))
{
using (var newFileStream = new FileStream(outputFilename, FileMode.Create))
{
var pdfReader = new PdfReader(existingFileStream);
var stamper = new PdfStamper(pdfReader, newFileStream);
var form = stamper.AcroFields;
var fieldKeys = form.Fields.Keys;
foreach (string fieldKey in fieldKeys)
{
form.SetField(fieldKey, "REPLACED!");
}
stamper.FormFlattening = true;
stamper.Close();
pdfReader.Close();
}
}
All works well only if I ommit the
stamper.FormFlattening = true;
line, but then the forms are visible as...forms.
When I add the this line, any values set to the form fields are lost, resulting in a blank form. I would really appreciate any advice.

Most likely you can resolve this when using iTextSharp 5.4.4 (or later) by forcing iTextSharp to generate appearances for the form fields. In your example code:
var form = stamper.AcroFields;
form.GenerateAppearances = true;

Resolved the issue by using a previous version of ITextSharp (5.4.3). Not sure what the cause is though...

I found a working solution for this for any och the newer iTextSharp.
The way we do it was:
1- Create a copy of the pdf temmplate.
2- populate the copy with data.
3- FormFlatten = true and setFullCompression
4- Combine some of the PDFs to a new document.
5- Move the new combined document and then remove the temp.
This way we got the issue with removed input and if we skipped the "formflatten" it looked ok.
However when we moved the "FormFlatten = true" from step 3 and added it as a seperate step after the moving etc was complete, it worked perfectly.
Hope I explained somewhat ok :)

In your PDF File, change the property to Visible, the Default value is Visible but not printable.

Reading text against the editable field in PDF to UI

In my website, a client will upload different types of PDF templates which contain editable fields. I want to read the text and editable fields from the PDF and display the text with corresponding fields in my web form. I have found solutions for reading the text and fields separately, but I am not able to map the fields against the corresponding text.
Reading text and getting fields using itextsharp but not able to map that text and field. for ex: in the pdf it is specified as FirstName: Thomas. Reading from the PDF and display it in the UI as Firstname(label): Thomas (textbox).
sample code i have used to get all the fields,
public string GetPDFFields()
{
string pdfTemplate = #"d:\1234.pdf";
var pdfReader = new PdfReader(pdfTemplate);
var outStream = new MemoryStream();
var stamper = new PdfStamper(pdfReader, outStream);
var form = stamper.AcroFields;
var fieldKeys = form.Fields.Keys;
StringBuilder sb = new StringBuilder();
foreach (string fieldKey in fieldKeys)
{
sb.Append(form.GetField(fieldKey)+"\r\n");
}
return sb.ToString();
}

Try to read use this code sample
http://simpledotnetsolutions.wordpress.com/2012/04/08/itextsharp-few-c-examples/

How to read PDF form data using iTextSharp?

I am trying to find out if it is possible to read PDF Form data (Forms filled in and saved with the form) using iTextSharp. How can I do this?

You would have to find out the field names in the PDF form. Get the fields and then read their value.
string pdfTemplate = "my.pdf";
PdfReader pdfReader = new PdfReader(pdfTemplate);
AcroFields fields = pdfReader.AcroFields.Fields;
string val = fields.GetField("fieldname");
Obviously in the code above, field name is the name of the PDF form field and the GetField method returns a string representation of that value.
Here is an article with example code that you could probably use. It shows how you can both read and write form fields using iTextSharp.

Maybe the iTextSharp library has changed recently but I wasn't able to get the accepted answer to work. Here is my solution:
var pdf_filename = "pdf2read.pdf";
using (var reader = new PdfReader(pdf_filename))
{
var fields = reader.AcroFields.Fields;
foreach (var key in fields.Keys)
{
var value = reader.AcroFields.GetField(key);
Console.WriteLine(key + " : " + value);
}
}
A very subtle difference, due to reader.AcroFields.Fields returning an IDictionary instead of just an AcroFields object.

If you are using Powershell, the discovery code for fields is:
Add-Type -Path C:\Users\Micah\Desktop\PDF_Test\itextsharp.dll
$MyPDF = "C:\Users\Micah\Desktop\PDF_Test\something_important.pdf"
$PDFDoc = New-Object iTextSharp.text.pdf.pdfreader -ArgumentList $MyPDF
$PDFDoc.AcroFields.Fields
That code will give you the names of all the fields on the PDF Document, "something_important.pdf".
This is how you access each field once you know the name of the field:
$PDFDoc.AcroFields.GetField("Name of the field here")

This worked for me!
Note the parameters when defining stamper! '\0', true
string TempFilename = Path.GetTempFileName();
PdfReader pdfReader = new PdfReader(FileName);
//PdfStamper stamper = new PdfStamper(pdfReader, new FileStream(TempFilename, FileMode.Create));
PdfStamper stamper = new PdfStamper(pdfReader, new FileStream(TempFilename, FileMode.Create), '\0', true);
AcroFields fields = stamper.AcroFields;
AcroFields pdfFormFields = pdfReader.AcroFields;
foreach (KeyValuePair<string, AcroFields.Item> kvp in fields.Fields)
{
string FieldValue = GetXMLNode(XMLFile, kvp.Key);
if (FieldValue != "")
{
fields.SetField(kvp.Key, FieldValue);
}
}
stamper.FormFlattening = false;
stamper.Close();
pdfReader.Close()

The PDF name is "report.pdf"..
The data field to be read into TextBox1 is "TextField25" in the PDF..
Dim pdf As String = "report.pdf"
Dim reader As New PdfReader(pdf)
Dim fields As AcroFields = reader.AcroFields
TextBox1.Text = fields.GetField("TextField25")
Important Note: This can be used ONLY IF the PDF is not flattened (means the fields should be editable) while it was created using iTextSharp..
i.e.
pdfStamper.FormFlattening = False
This is very simple.. And it works like a charm.. :)

If anybody is still wondering about this answer, this is how I extracted the text in the field (provided you know the field name):
PdfReader reader = new("filepath");
PdfDocument doc = new(reader);
PdfAcroForm form = PdfAcroForm.GetAcroForm(document, false);
Form.GetField("FieldNameHere").GetValueAsString();
Works for iText 7.1.16