How to remove observer

Question

I have an ARC enabled project

There are few observers added in viewDidLoad

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(getSipNotification:) name:@"getSipNotification" object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(syncExtensionData:) name:@"syncExtensionData" object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(showLocalNotification:) name:@"showLocalNotification" object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(outgoingCall:)  name:@"outgoingCall" object:nil]; 
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(playRingtone)  name:@"playRingtone" object:nil];

I want to remove all observers so I added following line in viewDidUnload

[[NSNotificationCenter defaultCenter] removeObserver:self];

Now my question is, is this remove all observers?

If not how can do it?

UPDATE

If I want to remove a single observer how can do it?

Can you help me please.

Please note that viewDidUnload: isn't a right place for removing observer in most cases. Most likely you should do it in dealloc, viewDidDissapear or something else. — wirrwarr, Oct 03 '13 at 10:03

Dharmbir Singh · Answer 1 · 2013-10-03T09:37:01.313

2

Yes, It will remove all observers.

 [[NSNotificationCenter defaultCenter] removeObserver:self];

And you can remove a particular observer like this...

[[NSNotificationCenter defaultCenter] removeObserver:self name:@"syncExtensionData" object:nil];

edited Oct 03 '13 at 09:37

answered Oct 03 '13 at 09:30

Dharmbir Singh

17,485
5
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score 2 · Answer 2 · answered Oct 03 '13 at 09:47

In my application i used this notification :

for particular observer remove this way :

 -(void)viewWillAppear:(BOOL)animated
 {

   [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(deviceRotatedFeedBackView:) name:UIDeviceOrientationDidChangeNotification object:nil];

}
-(void)deviceRotatedFeedBackView:(NSNotification*)notification
{
    //right whetever you want
}
 - (void)viewWillDisappear:(BOOL)animated
{

  [[NSNotificationCenter defaultCenter] removeObserver:self name:UIDeviceOrientationDidChangeNotification object:nil];
}

may be it will helpful to you.

score 1 · Answer 3 · answered Oct 03 '13 at 09:32

1

Yes it'll remove all the observers in your class.

You can use following to remove single observer:

[[NSNotificationCenter defaultCenter] removeObserver:self name:@"getSipNotification" object:nil];

To remove individual observer.

answered Oct 03 '13 at 09:32

Rushi

4,553
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score 0 · Answer 4 · answered Oct 03 '13 at 09:51

viewDidUnload is deprecated in iOS6 and later, so Your observer never be removed from notification center in iOS6 and later. To remove single observer try

 - (void)removeObserver:(id)notificationObserver name:(NSString *)notificationName object:(id)notificationSender

How to remove observer

4 Answers4