PDF 添加页码

复制from reportlab.lib.pagesizes import A4
from reportlab.pdfgen import canvas
from reportlab.lib.units import mm

# 为 PDF 每页添加页码（底部居中，起始页=1）
input_pdf = "input.pdf"
output_pdf = "output.pdf"

from PyPDF2 import PdfReader, PdfWriter
from reportlab.pdfgen import canvas
from io import BytesIO

reader = PdfReader(input_pdf)
writer = PdfWriter()

start_page = 1  # 起始页码
for i, page in enumerate(reader.pages):
    packet = BytesIO()
    c = canvas.Canvas(packet, pagesize=A4)
    c.setFont("Helvetica", 10)
    # 底部居中，距底边 20mm
    c.drawCentredString(A4[0]/2, 20*mm, str(start_page + i))
    c.save()
    packet.seek(0)
    overlay = PdfReader(packet)
    page.merge_page(overlay.pages[0])
    writer.add_page(page)

with open(output_pdf, "wb") as f:
    writer.write(f)
print(f"已添加页码，保存为 {output_pdf}")

复制package main

import (
	"fmt"
	"github.com/pdfcpu/pdfcpu/pkg/api"
	"github.com/pdfcpu/pdfcpu/pkg/pdfcpu"
	"os"
)

func main() {
	input := "input.pdf"
	output := "output.pdf"

	// 配置页码：底部居中，字体 Helvetica 10pt，起始页=1
	conf := pdfcpu.NewDefaultConfiguration()
	conf.Cmd = pdfcpu.ADDWATERMARK

	// 页码水印配置
	wm, err := pdfcpu.ParseTextWatermark("{{.PageNo}}", "pos:bc, font:Helvetica, size:10, scale:1, abs")
	if err != nil {
		fmt.Fprintf(os.Stderr, "解析水印失败: %v\n", err)
		os.Exit(1)
	}
	wm.OnTopOfContent = false // 页码在内容下方（不遮挡正文）

	// 执行添加页码
	if err := api.AddWatermarksFile(input, output, []*pdfcpu.Watermark{wm}, conf, nil); err != nil {
		fmt.Fprintf(os.Stderr, "添加页码失败: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("已添加页码，保存为 %s\n", output)
}

复制const { PDFDocument, StandardFonts, rgb } = require('pdf-lib');
const fs = require('fs');

async function addPageNumbers() {
  const pdfBytes = fs.readFileSync('input.pdf');
  const doc = await PDFDocument.load(pdfBytes);
  const font = await doc.embedFont(StandardFonts.Helvetica);
  const pages = doc.getPages();

  const startPage = 1;
  for (let i = 0; i < pages.length; i++) {
    const page = pages[i];
    const { width, height } = page.getSize();
    // 底部居中，距底边 20 点
    page.drawText(String(startPage + i), {
      x: width / 2 - 10,
      y: 20,
      size: 10,
      font: font,
      color: rgb(0, 0, 0),
    });
  }

  const pdfOut = await doc.save();
  fs.writeFileSync('output.pdf', pdfOut);
  console.log('已添加页码，保存为 output.pdf');
}

addPageNumbers().catch(console.error);