如何将页面的某段html转化为图片下载

使用html2canvas插件，先将html转化为canvas，再将canvas转为blob

const treeContainnerElem = document.getElementById('treeContent')
  // 控制最大宽度防止右边样式缺失
  let tempElemWidth = treeContainnerElem.style.width.slice(0, -2)
  treeContainnerElem.style.top = 0
  treeContainnerElem.style.left = 0
  let scale = tempElemWidth > allowMaxWidth ? allowMaxWidth / tempElemWidth : 1
  this.$nextTick(() => {
  html2canvas(treeContainnerElem, {
  useCORS: true, // 允许CORS跨域
  scale: scale
  }).then(canvas => {
  const downloadName = this.downloadName + '.jpg'
  canvas.toBlob(function (blob) {
  const eleLink = document.createElement('a')
  eleLink.download = downloadName
  eleLink.style.display = 'none'
  eleLink.href = URL.createObjectURL(blob) // 字符内容转变成blob地址
  document.body.appendChild(eleLink) // 触发点击
  eleLink.click()
  document.body.removeChild(eleLink) // 然后移除
  }, 'image/png', 1)
  // treeContainnerElem.removeChild(tempElem)
  this.downloadLoading = false
  })
  .catch(() => {
  this.downloadLoading = false
  })
  })
  },