node 跨域问题

node跨域有很多方法

1、引入 中间件cors 我觉的最好的方法

var express=require('express');
var cors=require('cors');
var app=express();
app.use(cors({
     origin:['http://localhost:8080'], //允许这个域访问
     methods:['GET','POST'], //只允许get post
     allweHeaders:['Conten-Type','Autorization'] //只允许带这两种请求头的链接
})) //一定要放在请求前

app.use('/', index);
app.use('/users', users);

2、允许了所有的跨域请求

var express = require('express');
var app = express();

var http=require('http');
app.all("*", function (req, res, next) {
  res.header('Access-Control-Allow-Origin', '*');
  res.header("Access-Control-Allow-Headers", "Content-Type,Content-Length, Authorization, Accept,X-Requested-With");
  res.header("Access-Control-Allow-Methods","PUT,POST,GET,DELETE,OPTIONS");
  if (req.method == 'OPTIONS') {
    res.send(200);
  } else {
    next();
  }
});