Bartender文件.btw(ANSI)进行base64加密存进数据库，下载文件时需要进行atob解码在转成bytes字节后，new Blob()才能得到ANSI编码的文本

使用element UI的upload组件

                <el-upload
                  action=""
                  :auto-upload="false"
                  :file-list="fileList"
                  :limit="1"
                  :multiple="false"
                  :on-change="handleChange"
                  :on-preview="handlePreview"
                  :on-error="uploadError"
                  :on-remove="removefile"
                  :show-file-list="true"
                  accept=".btw"
                  ref="upload"
                >
                  <el-button @click="handleExport()" slot="trigger" type="text">{{$t('template_define.button_upload')}}</el-button>
                </el-upload>    

methods方法

    // 文件上传触发
    handleChange (file, fileList) {
      let _this = this
      if (this.formdata.printMode !== 'Bartender') return
      this.formdata.remark = file.name
      let reader = new FileReader()
      reader.readAsDataURL(file.raw)
      reader.onload = function () {
        _this.fileList = fileList
        _this.bartenderstring = reader.result.substring(reader.result.indexOf('base64') + 'base64,'.length)
      }
    },
    decode (base64) {
      let decode = window.atob(base64)
      var len = decode.length
      var bytes = new Uint8Array(len)
      for (var i = 0; i < len; i++) {
        bytes[i] = decode.charCodeAt(i)
      }
      // let str = decodeURI(decode)
      return bytes
    },
    // 文件点击触发
    handlePreview (file) {
      try {
        let content = this.decode(this.bartenderstring)
        const blob = new Blob([content])
        let a = document.createElement('a');
        a.download = file.name + '.btw';
        a.href =  URL.createObjectURL(blob);
        let event = new MouseEvent('click');
        a.dispatchEvent(event);
      } catch (e) {
        console.log(e)
      }
    }