利用jsPDF实现图片转PDF及合并打印方案

import jsPDF from 'jspdf';
import { PDFDocument,  } from 'pdf-lib';

// pdf--pdfA--是使用jspdf将图片生成的pdf
// file--pdfB--是合并pdf需要的pdf格式
const jsPdfBytes = pdf.output('arraybuffer');
const file = await PDFDocument.load(jsPdfBytes);

if(x.FILE_TYPE == '.tif' || x.FILE_TYPE == '.tiff' ){
     const response = await fetch(imgUrl);
     const buffer = await response.arrayBuffer();
     const Tiff = require("tiff.js");
     const tiff = new Tiff({ buffer });
     imgUrl = tiff.toDataURL();
}

const imageWidth = 100;

async imgToPdf(arr) {
      const promises = [];
      arr.forEach(async (x)=>{
        const promise = new Promise(async (resolve,reject)=>{
          //jsPdf 仅支持JPG/JPEG/PNG/BMP格式,不支持tif
          let id = x.ID
          let imgUrl = window.URL.createObjectURL(x.FILE)
          //如果是tif或者tiff文件，需要转化后再进行 图片转pdf操作
          if(x.FILE_TYPE == '.tif' || x.FILE_TYPE == '.tiff' ){
            const response = await fetch(imgUrl);
            const buffer = await response.arrayBuffer();
            const Tiff = require("tiff.js");
            const tiff = new Tiff({ buffer });
            imgUrl = tiff.toDataURL();
          }
          const pdf = new jsPDF();
          //添加header
          //pdf.text('PDF Header', 10, 10);
          // 将图片绘制到pdf中
          const imageWidth = 100; // 设定图片的最大宽度
          const imageHeight = 0; // 设置为 0，将根据宽度等比例计算高度
          const img = new Image();
          img.src = imgUrl
          let finalWidth = imageWidth;
          let finalHeight = imageHeight;
          img.onload = function () {
            const width = img.width;
            const height = img.height;
            // 计算图片适应 PDF 页面的尺寸
            const aspectRatio = width / height;
            if (finalHeight === 0) {
              finalHeight = finalWidth / aspectRatio;
            } else if (finalWidth === 0) {
              finalWidth = finalHeight * aspectRatio;
            }
          };
          // 添加图片到 PDF
          pdf.addImage(imgUrl, 'JPEG', 10, 10, finalWidth, finalHeight, null, 'SLOW')
          const jsPdfBytes = pdf.output('arraybuffer');
          const file = await PDFDocument.load(jsPdfBytes);
          //const blob = new Blob([file], { type: 'application/PDF' })
          let obj = {
            ID: id,
            FILE: file
          }
          console.log("执行了------imgToPdf")
          resolve(obj)
        }).then((obj)=>{
          this.pdfFileArr.push(obj)
        }).catch((error)=>{
          this.loadLoading = false
          alert('错误信息为：'+error)
        })
        promises.push(promise);
      })
      return Promise.all(promises)
    },

async mergePdf(sortList) {
      console.log('最终需要合并的pdf数组', sortList)
      let files = sortList
      // 创建一个新的PDF文档
      const mergedPdf = await PDFDocument.create();
      // 遍历选择的每个文件
      for (let i = 0; i < files.length; i++) {
       /**
		这里为.pdf 文件的遍历操作
		通过FileReader 读取.pdf文件，转为合并pdf所需要的pdf类型
        const file = files[i];
        const url = window.URL.createObjectURL(file)
        const reader = new FileReader();
        // 读取文件内容
        const fileContents = await new Promise((resolve, reject) => {
          reader.onload = function (event) {
            resolve(event.target.result);
          };
          reader.onerror = function (event) {
            reject(new Error("文件读取错误。"));
          };
          reader.readAsArrayBuffer(file); //blob
        });
        // 将PDF文件添加到合并的PDF文档中
        const pdf = await PDFDocument.load(fileContents);
        console.log("合并pdf---", pdf)
        **/
        const pdf = files[i];
        const copiedPages = await mergedPdf.copyPages(
          pdf,
          pdf.getPageIndices()
        );
        copiedPages.forEach((page) => {
          mergedPdf.addPage(page);
        });
      }
      const uint8Array = await mergedPdf.save();
      let mergeBuffer = Buffer.from(uint8Array);
      const url = window.URL.createObjectURL(new Blob([mergeBuffer], { type: 'application/pdf;charset=utf-8' }));
      this.mergePdfUrl = url
      console.log("pdf合并完成")
      console.log("新合并的pdf--", url)
      console.log("新合并的pdf--", mergedPdf)
    },

<iframe ref="printPdf"  id="printIframe" 
            style="overflow:hidden;filter: Chroma(Color=white);border: none;width: 100%; height: 100%"
            :src="item.url + '#toolbar=0'"></iframe>
            <!-- #view=FitH,top -->

document.getElementById('printIframe').contentWindow.print();