uploadAttachmentsProps = {
 action: `/api/upload`,
 showUploadList: false, // 這里關閉自帶的列表
 beforeUpload: (info) => {
 /* 上傳前的鉤子，可以用來判斷類型，和大小 
 if ('是否符合類型') {
  return false
 }
 if ('是否符合類型') {
  return false
 }
 return true
 */
 }，
 onChange: (info) => {
 console.log(info)
 /*
  回調有三個參數(shù)
  {
   file: { ... },
   fileList: [ ... ],
   event: { ... }
  }
 */ 
 }
} 
<Upload {...uploadAttachmentsProps}>
 <a style={{marginRight: '10px'}}><Icon type="plus"></Icon>添加</a>
</Upload> 

const event = info.event
if (event) { // 一定要加判斷，不然會報錯
 let percent = Math.floor((event.loaded / event.total) * 100)

 this.setState({percent: percent})
 console.log(percent) // percent就是進度條的數(shù)值
}

const props = {
  action: this.state.action,
  fileList: fileList,
  data: {
    appid: appid,
    secret: secret,
  },
  headers: {'X-Requested-With': null},
  // accept: "image/*",
  accept: "image/jpg,image/jpeg,image/png,image/bmp",
  onChange: this.handleChange,
  beforeUpload: this.beforeUpload,
  onPreview: this.handlePreview,
  listType: "picture-card",
};


<Upload {...props}>
  {fileList.length >= this.state.length ? null : uploadButton}
</Upload>