ant-design/components/upload/demo/upload-png-only.md

order	title
7.1	zh-CN en-US 只上传 png 图片 Upload png file only

zh-CN

beforeUpload 返回 false 或 Promise.reject 时，只用于拦截上传行为，不会阻止文件进入上传列表（原因）。如果需要阻止列表展现，可以参照此例配合 onChange 进行实现。

en-US

beforeUpload only prevent upload behavior when return false or reject promise, the prevented file would still show in file list. Here is the example you can keep prevented files out of list by using onChange.

import React, { useState } from 'react';
import { Upload, Button, message } from 'antd';
import { UploadOutlined } from '@ant-design/icons';

const Uploader = () => {
  const [fileList, updateFileList] = useState([]);
  const props = {
    fileList,
    beforeUpload: file => {
      if (file.type !== 'image/png') {
        message.error(`${file.name} is not a png file`);
      }
      return file.type === 'image/png';
    },
    onChange: info => {
      console.log(info.fileList);
      // file.status is empty when beforeUpload return false
      updateFileList(info.fileList.filter(file => !!file.status));
    },
  };
  return (
    <Upload {...props}>
      <Button>
        <UploadOutlined /> Upload png only
      </Button>
    </Upload>
  );
};

ReactDOM.render(<Uploader />, mountNode);