Express解决跨域问题

放到APP.js里面就行

app.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();});