KVO on MKAnnotations

[leeus]

I have the following code in my

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation{
//Other Code
[newAnnotation addObserver:self forKeyPath:@"selected" options:NSKeyValueObservingOptionNew context:@"ANSELECTED"];
//Other Code
}

And I use the KVO to see when it is selected or not.

However when I then call

[mapView removeAnnotations:existingpoints];

I get a KVO error and can't work out the code to remove the observer. Any ideas on the code to remove it as the bit here doesn't work

An instance 0x3b13e0 of class MKAnnotationView is being deallocated while key value observers are still registered with it. Observation info is being leaked, and may even become mistakenly attached to some other object. Set a breakpoint on NSKVODeallocateBreak to stop here in the debugger. Here's the current observation info:

<NSKeyValueObservance 0x3afde0: Observer: 0x31dc20, Key path: selected, Options: <New: YES, Old: NO, Prior: NO> Context: 0x10f984, Property: 0x3afcf0>

Current removal code....

for (id annotation in mapView.annotations) {

[self removeObserver:annotation forKeyPath:@"selected"];

}

[Oliver Drobnik]

Originally Posted by leeus

I have the following code in my

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation{
//Other Code
[newAnnotation addObserver:self forKeyPath:@"selected" options:NSKeyValueObservingOptionNew context:@"ANSELECTED"];
//Other Code
}

And I use the KVO to see when it is selected or not.

However when I then call

[mapView removeAnnotations:existingpoints];

I get a KVO error and can't work out the code to remove the observer. Any ideas on the code to remove it as the bit here doesn't work

An instance 0x3b13e0 of class MKAnnotationView is being deallocated while key value observers are still registered with it. Observation info is being leaked, and may even become mistakenly attached to some other object. Set a breakpoint on NSKVODeallocateBreak to stop here in the debugger. Here's the current observation info:

<NSKeyValueObservance 0x3afde0: Observer: 0x31dc20, Key path: selected, Options: <New: YES, Old: NO, Prior: NO> Context: 0x10f984, Property: 0x3afcf0>

Current removal code....

for (id annotation in mapView.annotations) {

[self removeObserver:annotation forKeyPath:@"selected"];

}

KVO observers are registered in your annotations and NOT your mapview. So "self removeObserver:" cannot work. you'd have to use [annotation removeObserver instead.

[leeus]

Originally Posted by Oliver Drobnik

KVO observers are registered in your annotations and NOT your mapview. So "self removeObserver:" cannot work. you'd have to use [annotation removeObserver instead.

Thanks Oliver,

I get an error when I change it round to the correct way...

2010-05-10 07:12:30.766 LittleApp[4493:207] *** Terminating app due to uncaught exception 'NSRangeException', reason: 'Cannot remove an observer <LittleAppViewController 0x31ddf0> for the key path "selected" from <MyObject 0x3a0160> because it is not registered as an observer.'

[Oliver Drobnik]

Originally Posted by leeus

Thanks Oliver,

I get an error when I change it round to the correct way...

2010-05-10 07:12:30.766 LittleApp[4493:207] *** Terminating app due to uncaught exception 'NSRangeException', reason: 'Cannot remove an observer <LittleAppViewController 0x31ddf0> for the key path "selected" from <MyObject 0x3a0160> because it is not registered as an observer.'

Just make sure that you use exactly the same parameters you did for removing the observer as you did for registering it.

[brewem]

You'll need to send the remove message to the view associated with the annotation, not the annotation itself. Try the following...

	
	for (id <MKAnnotation> annotation in mapView.annotations) {			
		[[mapView viewForAnnotation:annotation] removeObserver:self forKeyPath:@"selected"];
	}