Go Requires Chilkat v11.7.0+

Put a Letterhead Behind the First Page of a PDF

See more PDF Watermark Examples

Demonstrates the pdfPage type, which places a page of another PDF as the watermark. It is the way to use a letterhead, a cover overlay or a vector logo that was saved as a PDF, and unlike an image it stays sharp at any size because it is drawn, not resampled. "zOrder" set to back puts it behind the existing content, where a letterhead belongs, and "pages" set to first restricts it to page one. Go

    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 two_page_memo.pdf

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

    pdf := chilkat.NewPdf()
    success = pdf.LoadFile("qa_data/pdf/two_page_memo.pdf")
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        return
    }

    json := chilkat.NewJsonObject()
    json.UpdateString("type","pdfPage")
    json.UpdateString("pdf.path","qa_data/pdf/letterhead.pdf")

    //  The page of the source PDF to use (1 by default).  "match" instead of a number places source
    //  page n on target page n, which suits a set of per-page backgrounds.
    json.UpdateInt("pdf.page",1)

    //  Behind the memo's own text, on page one, scaled to the page.
    json.UpdateString("zOrder","back")
    json.UpdateString("pages","first")
    json.UpdateString("scale.fit","page")
    json.UpdateString("id","letterhead")

    jsonOut := chilkat.NewJsonObject()
    success = pdf.Watermark("add",json,jsonOut)
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        return
    }

    fmt.Println("id: ", *jsonOut.StringOf("id"), " pages: ", *jsonOut.StringOf("pages"))

    success = pdf.WriteFile("qa_output/memo_letterhead.pdf")
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        return
    }

    //  Sample output:

    //  id: letterhead pages: 1

    pdf.DisposePdf()
    json.DisposeJsonObject()
    jsonOut.DisposeJsonObject()