IT技术 - React.useEffect 在 Express 应用程序中不起作用 - 吾爱随笔录

状态似乎没有改变或重新渲染。我曾尝试从 useEffect 内部进行日志记录，但没有任何react。知道如何让 useEffect 工作吗？

应用程序.js

var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');

var app = express();

// view engine setup
app.set('view engine', 'jsx');
app.engine('jsx', require('express-react-views').createEngine());

app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.get('bots/burrito', function(req, res, next) {
    //res.render('bot')
    res.render('bot')
});

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};
  console.log(err)
  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;

bot.jsx

import React from 'react';

const tutorials=(props)=>{
    const [a, setA] = React.useState('asdf')
    React.useEffect( ()=>{
       setA('asdfasfdasdfa')
    }, [] );
    return(
        <p>{a}</p>
    )
 }


module.exports = tutorials;

当我导航到时，https://localhost:3000/bots/burrito我会看到呈现的内容<p>asdf</p>并且它永远不会改变。