base64 excel类型base64转html在线显示

    parseBase64ToBlob(dataUrl, fileType) {
      const bstr = window.atob(dataUrl)
      let n = bstr.length
      const u8arr = new Uint8Array(n)
      while (n--) {
        u8arr[n] = bstr.charCodeAt(n)
      }
      return new Blob([u8arr], { type: fileType || 'pdf' })
    },

    previewHtmlByBase64(base64Str, fileType) {
      if (base64Str) {
        const myBlob = this.parseBase64ToBlob(base64Str, fileType)
        window.open(URL.createObjectURL(myBlob))
        const reader = new FileReader()
        reader.onload = function(event) {
          const content = reader.result // 内容就在这里
          const open = window.open('about:blank', '_blank')
          open.document.write(content)
        }
        reader.readAsText(myBlob)
      }
    },

this.previewHtmlByBase64(res.data.fileBase64, 'text/html;base64')