express跨域

express搭建服务器跨域问题

解决方案:

设置请求头为"Access-Control-Allow-Origin", "*"

具体代码

app.all('*', function(req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Headers", "X-Requested-With,Content-Type");
    res.header("Access-Control-Allow-Credentials", "true");
    res.header("Access-Control-Allow-Methods","PUT,POST,GET,DELETE,OPTIONS");
    res.header("X-Powered-By",' Express 4.17.1');
    res.header("Content-Type", "application/json;charset=utf-8");
    next();
  });
app.use('/api',Router)

记住:解决跨域问题的这个代码必须放在Api调用的前边,否则跨域代码不起作用