NSNotification not being sent when postNotificationName: called

I had the same problem. The reason is that I called removeObserver method at

- (void)viewDidDisappear:(BOOL)animated{

    NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];

   [notificationCenter removeObserver:self];

}

So check whether if you had called removeObserver before postNotification.

Tips: You can search the keyword "removeObserver" to find if you had called this function.

Basically it's all to do with the order of execution. If you've executed postNotificationName before addObserver, then this is an easy problem to have. Use breakpoints and step through the code :)

Your first breakpoint should stop here:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(updateView:) name:@"ScanCompleted" object:nil];

Then here:

[[NSNotificationCenter defaultCenter]postNotificationName:@"ScanCompleted" object:self];

Also, make sure the selector has a colon on. Because it's method signature will be:

- (void)updateView:(NSNotification *)notification;

All my code makes use of NSNotifications like so:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(updateView) name:@"ScanCompleted" object:nil];

[[NSNotificationCenter defaultCenter] postNotificationName:@"ScanCompleted" object:nil];

The first one is registering the notification and the second posting of the notification.

Change this:

[[NSNotificationCenter defaultCenter]postNotificationName:@"Event" object:self];

to this:

[[NSNotificationCenter defaultCenter]postNotificationName:@"Event" object:nil];

If your first notification is registered properly, newEventLoaded should be called.