尝试通过管道将读取流传送到服务器上的express get api响应时，出现events.js:174处的write after end错误

const express = require('express');
const fs = require('fs');

const app = express();

app.get('/api', (req, res) => {
  const readStream = fs.createReadStream('file.txt');

  readStream.on('open', () => {
    // 设置响应头，指定传输的内容类型
    res.setHeader('Content-Type', 'text/plain');
    // 将读取流通过管道传送到响应流中
    readStream.pipe(res);
  });

  readStream.on('error', (err) => {
    // 发生错误时，返回错误信息给客户端
    res.status(500).send(err.message);
  });
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});