let service      
       service = axios.create({
         baseURL: process.env.VUE_APP_BASE_URL // api 的 base_url
         // timeout: 5000 // 请求超时时间
       });
      service({
        method: 'get',
        url: '/api/petition/print',//文件流接口
        params: {
          xfbh: row.xfbh
        },
        headers: {
          'Content-Type': 'application/pdf;charset-UTF-8'
        },
        responseType: 'blob'
      }).then(response => {
        console.log(response)
        const binaryData = []
        binaryData.push(response.data)
        if (binaryData[0].size === 0) {
          this.$message.warning('无附件时的提示')
        } else {
          // 获取blob链接
          const pdfUrl = window.URL.createObjectURL(
            new Blob(binaryData, { type: 'application/pdf;charset-UTF-8' })
          )
          window.open(pdfUrl, '_blank')
        }
      })