Express 解决跨域请求

在app.js中配置跨域请求

//设置允许跨域访问该服务.
app.use((req, res, next) => {
    res.set({
        'Access-Control-Allow-Credentials': true,
        'Access-Control-Max-Age': 1728000,
        'Access-Control-Allow-Origin': req.headers.origin || '*',
        'Access-Control-Allow-Headers': 'X-Requested-With,Content-Type',
        'Access-Control-Allow-Methods': 'PUT,POST,GET,DELETE,OPTIONS',
        'Content-Type': 'application/json; charset=utf-8'
    })
    req.method === 'OPTIONS' ? res.status(204).end() : next()
})