#observer-management

Observer <object> was not registered as an observer – duplicate removeObserver call

When developing with Foundation’s NSNotificationCenter, developers often need to clean up observers in deinit or cleanup routines. Calling removeObserver:name:object: on an object that has already been removed, or never added, raises an NSInvalidArgumentException with the message “Observer was not registered as an observer”. The decision point is whether to

observer-managementexception-handlingfoundationTasadduq Burneyowner27.5K rep · 17 Jun 2023, 09:42 UTC