接口上传file文件，不使用上传组件

import axios from 'axios'
var formData = new FormData()
  formData.append('file', this.Blob2ImageFileForWXBrowser(data))//file文件得包放到后面就好了
  // formData.append('file', file)
  axios({
    headers: this.imageHeader,
    method: 'post',
    url: this.imageUploadUrl,
    data: formData
  }).then(response => {
    console.log('upload')
    console.log(response)
    if (this.imageType == 1) {
      this.ruleForm.imageCover = response.data.data
    } else if (this.imageType == 2) {
      this.ruleForm.wireframeCover = response.data.data
    }
  })
Blob2ImageFileForWXBrowser(obj) {
  return new window.File([obj], `${(new Date).getTime()}.png`)
},