爱可信onUploadProgress在我的请求返回错误

Question

我想知道我在这里做错了。

const options = {
    headers: { 
      'Content-Type': 'multipart/form-data'
    },
    onUploadProgress: (progressEvent) => {
      console.log(progressEvent)
      var percentCompleted = Math.floor((progressEvent.loaded * 100) / progressEvent.total);
      console.log(percentCompleted)
    }
  }

  axios.post(this.$data_static.api, formData, options)
  .then(function({data}) {
    console.log(data)
  }).catch(err => {
     console.log(err)
  })

并且console.log()中的返回值为0，我的axios请求返回catch() 谢谢！