node.js碰到跨域问题怎么办

首先在nodejs项目中 安装 express

npm install express

然后引入

var express = require("express");
var app = express();
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 , yourHeaderFeild');
  res.header('Access-Control-Allow-Methods', 'PUT, POST, GET, DELETE, OPTIONS');
  if (req.method == 'OPTIONS') {
    res.send(200);
  } else {
    next();
  }
});