RemoveNotification Not being called

Question

I am using NSNotificationCenter in a code .

[[NSNotificationCenter defaultCenter]addObserverForName:@"NextIndexNotification" object:nil queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification *note) {

    [self receiveTestNotification:note];
    [[NSNotificationCenter defaultCenter] removeObserver:note];


}];

- (void)receiveTestNotification:(NSNotification *) notification
{
    NSDictionary *userInfo = notification.userInfo;
    NSString *strServerResultID = [userInfo objectForKey:@"valServerResultID"];
}

//// And I am adding Notification center here ...

            dispatch_async(dispatch_get_main_queue(),^{
                NSDictionary *userInfo = [NSDictionary dictionaryWithObject:[NSString stringWithFormat:@"%@",[[PerformXMLXPathQuery(responseData,xPathQuery) objectAtIndex:0] valueForKey:kNodeContent]] forKey:@"valServerResultID"];
                [[NSNotificationCenter defaultCenter] postNotificationName:@"NextIndexNotification" object:self userInfo:userInfo];

            });

in this code , remove notification doesn't being called and my code move to infinite loop .

where am I doing wrong ?

I'm not sure if it solves your problem but I see that you're removing the notification, not the observer — Andrey Chernukha, Aug 22 '14 at 12:11
A couple of things: 1. What is the function receiveTestNotification doing with its reference to note? If at any point you have create a strong reference to it, you may not be able to remove it. 2. Where are you creating the notification itself? In other words, there is not enough info to answer your question as written. — joelg, Aug 22 '14 at 12:12
this http://stackoverflow.com/questions/8477629/why-doesnt-remove-observer-from-nsnotificationcenteraddobserverfornameusingbl?rq=1 may help — gro, Aug 22 '14 at 12:34

Gereon · Answer 1 · 2014-08-25T12:09:25.563

0

Instead of passing note (which is the Notification itself, not the observer), pass the return value from the addObserverForName call to removeObserver, like this:

__block id observer = [[NSNotificationCenter defaultCenter] addObserverForName:@"NextIndexNotification" 
                      object:nil 
                       queue:[NSOperationQueue mainQueue] 
                  usingBlock:^(NSNotification *note)
{
    [self receiveTestNotification:note];
    [[NSNotificationCenter defaultCenter] removeObserver:observer];
}];

edited Aug 25 '14 at 12:09

answered Aug 22 '14 at 12:48

Gereon

17,258
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Ummm...the docs say to pass whatever you get back from the `addObserverForName:` method. – Phillip Mills Aug 22 '14 at 12:50
@PhillipMills you are right, I misread the question. I've updated my answer. – Gereon Aug 25 '14 at 12:10

score 0 · Answer 2 · answered Aug 22 '14 at 13:11

0

Try
[[NSNotificationCenter defaultCenter] removeObserver:nil];

answered Aug 22 '14 at 13:11

Parag Shinde

176
11

score 0 · Answer 3 · answered Aug 22 '14 at 13:40

0

Remove notification by using blocks.

[[NSNotificationCenter defaultCenter] removeObserver:self];

answered Aug 22 '14 at 13:40

josh

1,681
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RemoveNotification Not being called

3 Answers3