主要通过html2canvas和jspdf两个插件实现

通过html2canvas将HTML页面转换成图片，然后再将图片转换成base64，通过jspdf生成pdf文件

1、安装插件

npm install html2canvas jspdf --save

2、写实现方法

import html2Canvas from 'html2canvas'
import JsPDF from 'jspdf'

export default (elementId, fileName) => {
  if (!elementId) throw new Error("请传入元素id")
  const container = document.querySelector(`#${elementId}`)
  const canvas = document.createElement("canvas")
  const contentWidth = container.clientWidth
  const contentHeight = container.clientHeight
  const scale = window.devicePixelRatio
  const canvasCcale = 3
  canvas.width = contentWidth * canvasCcale;
  canvas.height = contentHeight * canvasCcale;
  canvas.getContext("2d").scale(canvasCcale, canvasCcale);
  const opts = {
    scale: scale,
    canvas: canvas,
    width: contentWidth,
    height: contentHeight,
    useCORS: true,
  };
  html2Canvas(container, opts).then(function (canvas) {
    let contentWidth = canvas.width
    let contentHeight = canvas.height
    let pageHeight = contentWidth / 592.28 * 841.89
    let leftHeight = contentHeight
    let position = 0
    let imgWidth = 595.28
    let imgHeight = 592.28 / contentWidth * contentHeight
    let pageData = canvas.toDataURL('image/jpeg', 1.0)
    let PDF = new JsPDF('', 'pt', 'a4')
    if (leftHeight < pageHeight) {
      PDF.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight)
    } else {
      while (leftHeight > 0) {
        PDF.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
        leftHeight -= pageHeight
        position -= 841.89
        if (leftHeight > 0) {
          PDF.addPage()
        }
      }
    }
    PDF.save(fileName + '.pdf')
  })
}

3、 引入并调用

import htmlToPdf from "@/utils/htmlToPdf"
htmlToPdf('domID', '文件名称')

也可以写成vue插件方式

1、定义方法

import html2Canvas from 'html2canvas'
import JsPDF from 'jspdf'
export default {
  install (Vue, options) {
    Vue.prototype.htmlToPdf = function (elementId, fileName) {
      ....
      ....
    }
  }
}

2、引入注册

import htmlToPdf from '@/utils/htmlToPdf'
Vue.use(htmlToPdf)

3、使用

<el-button type="primary" @click="htmlToPdf('#domID', 'fileName')">下载</el-button>

遇到的问题：解决方案