兼容ie——下载base64pdf格式文件

1.URL转blob

dataURLtoBlob (dataurl) {
   const bstr = atob(dataurl)
   let n = bstr.length
   const u8arr = new Uint8Array(n)
   while (n--) {
     u8arr[n] = bstr.charCodeAt(n)
   }
   return new Blob([u8arr], { type: 'pdf' }) // pdf下载
   // return new Blob([u8arr], { type: 'application/vnd.ms-excel' })    // 表格下载
 },

// 兼容IE浏览器下载文件
    getIEDown (data, companyName, projectName) {
      // 兼容ie浏览器写法
      const URL = this.dataURLtoBlob(data)
      const reader = new FileReader()
      reader.readAsDataURL(URL)
      reader.onload = function (e) {
        if (window.navigator.msSaveOrOpenBlob) {
          const bstr = atob(e.target.result.split(',')[1])
          let n = bstr.length
          const u8arr = new Uint8Array(n)
          while (n--) {
            u8arr[n] = bstr.charCodeAt(n)
          }
          const blob = new Blob([u8arr])
          window.navigator.msSaveOrOpenBlob(blob, `${companyName}-${projectName}.pdf`)
        } else {
          const a = document.createElement('a')
          a.download = `${companyName}-${projectName}.pdf`
          a.href = e.target.result
          document.body.appendChild(a)
          a.click()
          document.body.removeChild(a)
        }
      }
    },

this.getIEDown(data, this.companyName, this.projectName)

2.base64转blob

base64ToArrayBuffer (data) {
    let binaryString = window.atob(data)
    let binaryLen = binaryString.length
    let bytes = new Uint8Array(binaryLen)
    for (let i = 0; i < binaryLen; i++) {
      let ascii = binaryString.charCodeAt(i)
      bytes[i] = ascii
    }
    return bytes
  },

base64 (data, types, name) => {
  let arrBuffer = this.base64ToArrayBuffer(data)
  let newBlob = new Blob([arrBuffer], { type: types })
  // 兼容IE
  if (window.navigator && window.navigator.msSaveOrOpenBlob) {
    // window.navigator.msSaveOrOpenBlob(newBlob)
    window.navigator.msSaveOrOpenBlob(newBlob, name)
  }
  let data1 = window.URL.createObjectURL(newBlob)
  let link = document.createElement('a')
  document.body.appendChild(link) // required in FF, optional for Chrome
  link.href = data1
  link.download = name
  link.click()
  window.URL.revokeObjectURL(data1)
  link.remove()
}

this.base64(data, 'mime', '下载文件名称')