.NET Core C# Requires Chilkat v11.7.0+

Page Numbers, Dates and the File Name in a PDF Watermark

See more PDF Watermark Examples

Demonstrates the placeholders a text watermark understands, each replaced per page as the watermark is added: {page} is the page number, {pages} the page count, {date:FORMAT} the current local date and time, and {filename} the name of the file that was loaded. Two braces give a literal brace. pageNumber.start sets what {page} is on the first page, which is how a numbering that ignores a cover is produced, and pageNumber.style formats both {page} and {pages} as decimal, romanUpper, romanLower, letterUpper or letterLower. .NET Core C#

bool success = false;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  The PDF used in this example is available at four_pages.pdf

Chilkat.Pdf pdf = new Chilkat.Pdf();
success = pdf.LoadFile("qa_data/pdf/four_pages.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Chilkat.JsonObject json = new Chilkat.JsonObject();
json.UpdateString("type","text");
json.UpdateString("text","Page {page} of {pages}  -  printed {date:yyyy-MM-dd HH:mm}  -  {filename}");
json.UpdateString("id","pagefoot");
json.UpdateString("position.align","bottom");
json.UpdateNumber("position.margin","24");
json.UpdateNumber("font.size","9");
json.UpdateString("color","#505050");

Chilkat.JsonObject jsonOut = new Chilkat.JsonObject();
success = pdf.Watermark("add",json,jsonOut);
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Debug.WriteLine("footer pages: " + jsonOut.StringOf("pages"));

//  Roman numerals that start at i on page 2, so that a cover page is not numbered.
Chilkat.Pdf pdf2 = new Chilkat.Pdf();
success = pdf2.LoadFile("qa_data/pdf/four_pages.pdf");
if (success == false) {
    Debug.WriteLine(pdf2.LastErrorText);
    return;
}

Chilkat.JsonObject json2 = new Chilkat.JsonObject();
json2.UpdateString("type","text");
json2.UpdateString("text","- {page} -");
json2.UpdateString("id","roman");
json2.UpdateString("pages","2-");
json2.UpdateInt("pageNumber.start",1);
json2.UpdateString("pageNumber.style","romanLower");
json2.UpdateString("position.align","bottom");
json2.UpdateNumber("font.size","10");
success = pdf2.Watermark("add",json2,jsonOut);
if (success == false) {
    Debug.WriteLine(pdf2.LastErrorText);
    return;
}

Debug.WriteLine("roman pages: " + jsonOut.StringOf("pages"));

success = pdf.WriteFile("qa_output/four_pages_numbered.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

//  Sample output:

//  footer pages: 1-4
//  roman pages: 2-4