NodeJS设置Header解决跨域问题

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();  }});