B4X 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. B4X

Dim success As Boolean = 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

Dim pdf As ChilkatPdf
pdf.Initialize("pdf")
success = pdf.LoadFile("qa_data/pdf/four_pages.pdf")
If success = False Then
    Log(pdf.LastErrorText)
    Return
End If


Dim json As ChilkatJsonObject
json.Initialize
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")

Dim jsonOut As ChilkatJsonObject
jsonOut.Initialize
success = pdf.Watermark("add", json, jsonOut)
If success = False Then
    Log(pdf.LastErrorText)
    Return
End If

Log("footer pages: " & jsonOut.StringOf("pages"))

'  Roman numerals that start at i on page 2, so that a cover page is not numbered.
Dim pdf2 As ChilkatPdf
pdf2.Initialize("pdf2")
success = pdf2.LoadFile("qa_data/pdf/four_pages.pdf")
If success = False Then
    Log(pdf2.LastErrorText)
    Return
End If

Dim json2 As ChilkatJsonObject
json2.Initialize
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 Then
    Log(pdf2.LastErrorText)
    Return
End If

Log("roman pages: " & jsonOut.StringOf("pages"))

success = pdf.WriteFile("qa_output/four_pages_numbered.pdf")
If success = False Then
    Log(pdf.LastErrorText)
    Return
End If


'  Sample output:

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