ios - UIViewController add和remove observer的时机

Answer 1

First of all, VC1 and VC2 have nothing to do with each other. How did you monitor them? ?
Isn't the removal of the listener always done when the listening page is dealloc?
Secondly: I always do this kind of thing on notice. If the deletion is successful, a notification will be sent to notify the page that needs to be changed to request data again (that is, refresh).

Answer 2

同意楼上，相隔太远只能发通知

Answer 3

Just put it in dealloc