node.js设置跨域

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"); res.header("X-Powered-By",' 3.2.1') if(req.method=="OPTIONS") res.send(200);/*让options请求快速返回*/ else next(); });