methods:{
  //下载文件
    filerightDown(index,fileName) {//index 接口参数  fileName文件名字
      var _this = this;
      var fileName = fileName;
      this.$http({
        method: "post",url: this.HOST + api.download,params: {
          fileId: index
        },responseType:'arraybuffer'
      })
        .then(res => {
          this.download(res.data,fileName);
        })
        .catch(req => {
          console.log("下载失败",req);
        });
    },// 下载文件
    download (data,fileName) {
        if (!data) {
            return
        }
        let url = window.URL.createObjectURL(new Blob([data]));
        let link = document.createElement('a');
        link.style.display = 'none';
        link.href = url;
        link.setAttribute('download',fileName);
        document.body.appendChild(link);
        link.click();
    },}