express 设置允许跨域访问

//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-Control-Allow-Headers’, ‘Content-Type’);

res.header(‘Access-Control-Allow-Methods’, ‘*’);

res.header(‘Content-Type’, ‘application/json;charset=utf-8’);

next();

});

app.get(’/hello’, function (req, res) {

res.json({})

});

const server = app.listen(8082, function () {

console.log(‘Express app server listening on port %d’, server.address().port);

});