B4X Requires Chilkat v11.7.0+

Watermark Only Some of a PDF's Pages

See more PDF Watermark Examples

Demonstrates choosing the pages to stamp. "pages" takes all (the default), first, last, odd, even, or a list of 1-based pages and ranges such as 1,3,5-9,12- where a trailing dash means "to the end". "excludePages" takes the same syntax and is applied afterwards, which is how you say "every page except the cover". The result reports the pages the watermark actually landed on. 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

Log("pages in the document: " & pdf.NumPages)

Dim json As ChilkatJsonObject
json.Initialize
Dim jsonOut As ChilkatJsonObject
jsonOut.Initialize
json.UpdateString("type", "text")
json.UpdateString("text", "INTERNAL")
json.UpdateString("id", "internal")

'  Every page except the first.
json.UpdateString("pages", "all")
json.UpdateString("excludePages", "1")
success = pdf.Watermark("add", json, jsonOut)
If success = False Then
    Log(pdf.LastErrorText)
    Return
End If

Log("every page but the cover: " & jsonOut.StringOf("pages"))

'  A list of pages and ranges, on a second copy of the document.
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", "APPENDIX")
json2.UpdateString("id", "appendix")
json2.UpdateString("pages", "2,4-")
success = pdf2.Watermark("add", json2, jsonOut)
If success = False Then
    Log(pdf2.LastErrorText)
    Return
End If

Log("page 2 and 4 onwards: " & jsonOut.StringOf("pages"))

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


'  Sample output:

'  pages in the document: 4
'  every page but the cover: 2-4
'  page 2 and 4 onwards: 2,4