Within an App I make use of several viewcontrollers. On one viewcontroller an observer is initialized as follows:
[[NSNotificationCenter defaultCenter] removeObserver:self name:@"MyNotification" object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(myMethod:) name:@"MyNotification" object:nil];
Even when removing the NSNotification
before initializing the number of executions of myMethod:
is being summed up by the amount of repeated views on the respective viewcontroller.
Why does this happen and how can I avoid myMethod: being called more then once.
Note: I made sure by using breakpoints that I did not made mistakes on calling postNotification multiple times.
Edit: This is how my postNotification looks like
NSArray * objects = [NSArray arrayWithObjects:[NSNumber numberWithInt:number],someText, nil];
NSArray * keys = [NSArray arrayWithObjects:@"Number",@"Text", nil];
NSDictionary * userInfo = [NSDictionary dictionaryWithObjects:objects forKeys:keys];
[[NSNotificationCenter defaultCenter] postNotificationName:@"myNotification" object:self userInfo:userInfo];
edit: even after moving my subscribing to viewwillappear: I get the same result. myMethod: is called multiple times. (number of times i reload the viewcontroller).
-(void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[[NSNotificationCenter defaultCenter] removeObserver:self name:@"MyNotification" object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(myMethod:) name:@"MyNotification" object:nil];
}
edit: something seems wrong with my lifecycle. ViewDidUnload and dealloc are not getting called, however viewdiddisappear is getting called.
The way I push my Viewcontroller to the stack is as follows where parent is a tableview subclass (on clicking the row this viewcontroller is initiated:
detailScreen * screen = [[detailScreen alloc] initWithContentID:ID andFullContentArray:fullContentIndex andParent:parent];
[self.navigationController pushViewController:screen animated:YES];
Solution:
Moving removal of nsnotification to viewdiddisappear did the trick. Thanks for guidance!
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