解决nodejs+socketio的cors跨域报错问题

原报错：

Access to XMLHttpRequest at 'http://127.0.0.1:3008/socket.io/?EIO=4&transport=polling&t=ObAPQBP' from origin 'http://127.0.0.1:5500' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

经过尝试发现使用cors库或者手动加入cors请求头无法解决，最终通过以下方法解决：‘’

const io = socketIo(server,{//设置cors
    cors: {
      origin: "*",
      methods: ["GET", "POST"],
      allowedHeaders: ["my-custom-header"],
      credentials: true
    }}
);