Nodejs跨域

如果需要开方跨域访问

module.exports = function allowCrossDomain(req, res, next) {
  res.header('Access-Control-Allow-Origin', '*');
  res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE,OPTIONS');
  res.header(
    'Access-Control-Allow-Headers',
    'X-Requested-With, Content-Type, Content-Length, Authorization, Accept'
  );

  // intercept OPTIONS method
  if (req.method === 'OPTIONS') {
    res.sendStatus(200);
  } else {
    next();
  }
};

如果不用中间件, 直接手撸那么是这样的:

//跨域会引起一次option
if('OPTIONS'===req.method){
  res.writeHead(200, {
    'Content-Type': type,
    'Access-Control-Allow-Origin': '*',
    'Access-Control-Allow-Methods': 'GET,PUT,POST,DELETE,OPTIONS',
    'Access-Control-Allow-Headers':
    'X-Requested-With, Content-Type, Content-Length, Authorization, Accept',
  });
  res.end();

}

//然后再你真正要跨域的方法里面也这么写head