使用axios实现上传图片进度条功能

 onUploadProgress: function (progressEvent) {
  // 对原生进度事件的处理
 },

 uploadPhoto(payload,callback1,callback2){
    axios({
      url:BASE_URL + '/handler/material/upload',
      method:'post',
      onUploadProgress:function(progressEvent){ //原生获取上传进度的事件
        if(progressEvent.lengthComputable){
          //属性lengthComputable主要表明总共需要完成的工作量和已经完成的工作是否可以被测量
          //如果lengthComputable为false，就获取不到progressEvent.total和progressEvent.loaded
          callback1(progressEvent);
        }
      },
      data:payload
    }).then(res =>{
      callback2(res.data);
    }).then(error =>{
      console.log(error)
    })
  }

<mt-progress :value="precent" :bar-height="10">
   <div slot="end">{{Math.ceil(precent)}}%</div>
  </mt-progress>

const _this = this;
API.uploadPhoto(fd,(res) =>{
 let loaded = res.loaded,
   total = res.total;
   _this.$nextTick(() =>{
    _this.precent = (loaded/total) * 100;
   })
},(res) =>{
  if(res.code === '200'){
    MessageBox.alert('图片上传成功').then(action => {
     console.log('ok');
    });
  }
})