Session expiration means cross-domain understanding
If the session expires, the filter judges the jump, but if it is an ajax request, because its callback method returns, it needs to add js to the page for additional processing.
For general mvc requests, you can jump directly.
In addition: only ajax has a request for boasting a domain name, other httpClient and mvc requests do not exist, and httpClient can be used to process ajax cross-domain requests (that is, use it as an intermediate proxy) (or datatype: Jsonp can achieve cross-domain), the same Ajax requests from one server (same domain name) will not have cross-domain problems