import html2canvas from "html2canvas"
import JSPDF from "jspdf"

封装 printPdf.js

// 导出页面为PDF格式
import html2canvas from "html2canvas"
import JSPDF from "jspdf"
export default {
    // eslint-disable-next-line
  install (Vue, options) {
    Vue.prototype.ExportSavePdf = function (htmlTitle, currentTime) {
      var element = document.getElementById("pdfCentent")
      console.log();
      html2canvas(element, {
        logging: false,
        dpi:450,
        scale:3,
      }).then(function (canvas) {
        // console.log(canvas);
        // canvas.style = 'font-weight:500'
        var pdf = new JSPDF("l", "mm", "a4") // A4纸，纵向  第一个参数 l：横向 p：纵向 
        var ctx = canvas.getContext("2d")
        //关闭抗锯齿
        ctx.mozImageSmoothingEnabled = false;
        ctx.webkitImageSmoothingEnabled = false;
        ctx.msImageSmoothingEnabled = false;
        ctx.imageSmoothingEnabled = false;
        // return
        var a4w = 277; var a4h = 190 // A4大小，210mm x 297mm，因为是横向 宽高反着写  四边各保留20mm的边距，显示区域170x257
        var imgHeight = Math.floor(a4h * canvas.width / a4w) // 按A4显示比例换算一页图像的像素高度
        var renderedHeight = 0
 
        while (renderedHeight < canvas.height) {
          var page = document.createElement("canvas")
          page.width = canvas.width
          page.height = Math.min(imgHeight, canvas.height - renderedHeight)// 可能内容不足一页
 
          // 用getImageData剪裁指定区域，并画到前面创建的canvas对象中
          page.getContext("2d").putImageData(ctx.getImageData(0, renderedHeight, canvas.width, Math.min(imgHeight, canvas.height - renderedHeight)), 0, 0)
          pdf.addImage(page.toDataURL("image/jpeg", 1.0), "JPEG", 10, 10, a4w, Math.min(a4h, a4w * page.height / page.width)) // 添加图像到页面，保留10mm边距
 
          renderedHeight += imgHeight
          if (renderedHeight < canvas.height) { pdf.addPage() }// 如果后面还有内容，添加一个空页
          // delete page;
        }
        pdf.save(htmlTitle + currentTime)
      })
    }
  }
}

import htmlToPdf from "@/plugins/printPdf"

Vue.use(htmlToPdf)

2、导出文件对象

  const pdfOutput = pdf.output("blob")
  let fileName = Date.now() + '.pdf'
  let fileBlob = pdfOutput
  fileBlob.lastModifiedDate = new Date()  // 文件最后的修改日期
  fileBlob.name = fileName           // 文件名
  let files = new File([fileBlob], fileName, { type: fileBlob.type, lastModified: Date.now() })
  console.log(files);