axios 上传下载显示进度

let self = this
this.axios.put(this.uploadUrl, this.files[0], {
  headers: {
    'Content-Type': 'multipart/form-data'
  },
  transformRequest: [function (data) {
    return data
  }],
onDownloadProgress: 

 progressEvent => {
    let complete = (progressEvent.loaded / progressEvent.total * 100 | 0) + '%'
    self.uploadMessage = '上传 ' + complete
  },

onUploadProgress: progressEvent => { let complete = (progressEvent.loaded / progressEvent.total * 100 | 0) + '%' self.uploadMessage = '上传 ' + complete } }) .then((response) => { if (response.status === 200) { self.uploadMessage = '上传成功！' } })