element 上传组件不支持文件夹上传，。。。使用input的webkitdirectory属性可上传文件夹

<input ref="file"  class="fileUploaderClass" type='file' name="file" webkitdirectory @change.stop="changesData"/>


changesData () {
console.log(this.$refs.file.files)
 this.fileList = this.$refs.file.files  // 获取filelist
 },
// 上传
 uploadFile () {
      let formData = new window.FormData()
      for (let i = 0; i < this.fileList.length; i++) {  // 每个file append到formdata里
        formData.append('file', this.fileList[i])
      }
      let url = Vue.prototype.API_URL + '/imageCompare'
      axios({
        method: 'post',
        url: url,
        data: formData,
        headers: {'Content-Type': 'multipart/form-data'}
      }).then(function (res) {
      })
    },