vue中Button按钮下载后端返回的文件

HTML

<el-button
  type="primary"
  plain
  icon="el-icon-upload"
  size="mini"
  @click="exportFile"
  >下载已回复清单
</el-button>

JS

/* a标签下载django后端返回的文件 */
exportFile() {
  DownloadGuanMaiAbnormal().then(res => {
    // 文件下载
    const blob = new Blob([res], {
      type: "application/vnd.ms-excel"
    });
    let link = document.createElement("a");
    link.href = URL.createObjectURL(blob);
    link.setAttribute("download", "文件名称.xlsx");
    link.click();
    link = null;
    this.$message.success("导出成功");
  });
},