nodejs解决跨域问题

router.all('*', function(req, res, next) {

    res.header("Access-Control-Allow-Origin", "*");

    res.header("Access-Control-Allow-Headers", "X-Requested-With");

    res.header("Access-Control-Allow-Methods","PUT,POST,GET,DELETE,OPTIONS");

    res.header("X-Powered-By",' 3.2.1')

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

    next();

});