import { useEffect } from 'react';
import { useHistory } from 'react-router-dom';

// 获取用于微信授权的 code，卸载后会自动清除
export const useWxCode = () => {
  const history = useHistory();
  useEffect(()=>{const searchParams = new URLSearchParams(window.location.search);
    const urlCode = searchParams.get('code');
    const localCode = sessionStorage.getItem('code');
    if (!urlCode && !localCode) {
      const appid = 'xxxxxxxx'; // 微信授权的公众号的appid
      const redirectUrl = encodeURIComponent(window.location.href);
      window.location.href = `https://open.weixin.qq.com/connect/oauth2/authorize?appid=${appid}&redirect_uri=${redirectUrl}&response_type=code&scope=snsapi_base&state=123#wechat_redirect`;
    } else if (urlCode) {
      sessionStorage.setItem('code', urlCode);
      history.goBack();
    }
    return ()=>sessionStorage.removeItem('code');
  },[]);
  
  return sessionStorage.getItem('code');
}

import React from 'react';
// 引入useWxCode.js
import { useWxCode } from '@/utils/useWxCode';

const Test = () => {
  const code = useWxCode();

  return (
    <div>
      测试  
    </div>
  )    
}    

export default Test;