---
title: sessionDidBecomeActiveNotification
framework: appkit
role: symbol
role_heading: Type Property
path: appkit/nsworkspace/sessiondidbecomeactivenotification
---

# sessionDidBecomeActiveNotification

A notification that the workspace posts after a user session switches in.

## Declaration

```swift
class let sessionDidBecomeActiveNotification: NSNotification.Name
```

## Discussion

Discussion This notification allows an app to re-enable some processing, such as when a switched-out session switches back in. The notification object is the shared NSWorkspace instance. The notification doesn’t contain a userInfo dictionary. important: To receive this notification, use notificationCenter to register for it. If you use a different notification center to register, you won’t receive the notification. To observe this notification using Swift concurrency, use NSWorkspace.SessionDidBecomeActiveMessage.

## See Also

### Responding to Environment Notifications

- [willLaunchApplicationNotification](appkit/nsworkspace/willlaunchapplicationnotification.md)
- [didLaunchApplicationNotification](appkit/nsworkspace/didlaunchapplicationnotification.md)
- [didTerminateApplicationNotification](appkit/nsworkspace/didterminateapplicationnotification.md)
- [sessionDidResignActiveNotification](appkit/nsworkspace/sessiondidresignactivenotification.md)
- [didHideApplicationNotification](appkit/nsworkspace/didhideapplicationnotification.md)
- [didUnhideApplicationNotification](appkit/nsworkspace/didunhideapplicationnotification.md)
- [didActivateApplicationNotification](appkit/nsworkspace/didactivateapplicationnotification.md)
- [didDeactivateApplicationNotification](appkit/nsworkspace/diddeactivateapplicationnotification.md)
- [didRenameVolumeNotification](appkit/nsworkspace/didrenamevolumenotification.md)
- [didMountNotification](appkit/nsworkspace/didmountnotification.md)
- [willUnmountNotification](appkit/nsworkspace/willunmountnotification.md)
- [didUnmountNotification](appkit/nsworkspace/didunmountnotification.md)
- [didChangeFileLabelsNotification](appkit/nsworkspace/didchangefilelabelsnotification.md)
- [activeSpaceDidChangeNotification](appkit/nsworkspace/activespacedidchangenotification.md)
- [didWakeNotification](appkit/nsworkspace/didwakenotification.md)