<div class=" "  ref="pdfDownload"  > 
        <slot></slot> 
 </div>

  this.getPdf5('pdfDownload',this.title) 

<template></template>
<script>
// 导出页面为PDF格式
import html2Canvas from 'html2canvas'
import JsPDF from 'jspdf'
export default {
  install(Vue, options) {
    Vue.prototype.getPdf5 = function (domRef, title) {
      var title = title
      var c = document.createElement('canvas')
      var dom = this.$refs[domRef]
      var opts = {
        scale: 2,
        canvas: c,
        logging: true,
        width: dom.offsetWidth,
        height: dom.offsetHeight,
      }
      c.width = dom.offsetWidth * 2
      c.height = dom.offsetHeight * 2
//       c.getContext('2d').scale(2, 2)
      c.getContext('2d')
      html2Canvas(dom, 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(title + '.pdf')
      })
    }
  },
}
</script>