//demo const express = require('express'); const app = express(); //设置允许跨域访问该服务. app.all(’’, function (req, res, next) { res.header(‘Access-Control-Allow-Origin’, '’); //Access-Control-Allow-Headers ,可根据浏览器的F12查看,把对应的粘贴在这里就行 res.header(‘Access-Contro…