iphone CLLocationmanager Region monitoring callbacks not triggered
core-location, iphone, region, xcode
Solution
the region tracking stuff is for low granularity position tracking and is triggered on cell location boundaries, so if you don't cross a cell boundary, you will never get your regions checked. I had the same issues and researched this and a different website had a comment about this which pointed to this apple forum:
https://devforums.apple.com/message/251046#251046
If you read all the comments you will understand why this is not working.
I am trying a work around where I define my own NSSets to contain tracked CLRegions and occupied CLRegions and then when I get a locationManager:didUpdateToLocation:fromLocation: callback, I check all the regions in my tracked set to see if I was NOT in the inRegions set but now am in the tracked region (add to inRegions and call back with enterRegion) or if I was inRegion but now am not (remove from inRegions and call back with exitRegion). It is a work in progress now.
Problem
I am trying to use monitoring regions to track if users have visited landmarks. the location manager is initialized in a viewcontroller along with a mapkit in viewdidload of the view controller: ``` if (self.locationManager == nil) { // NSLog(@"creating location manager"); self.locationManager = [[CLLocationManager alloc] init]; locationManager.delegate = self; locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation; locationManager.distanceFilter = kCLDistanceFilterNone; } NSSet* set=[locationManager monitoredRegions]; if ([CLLocationManager regionMonitoringAvailable] && [CLLocationManager regionMonitoringEnabled]) { NSLog(@"region monitoring okay"); NSLog(@"monitored regions: %@",set); } ``` i get the NSLogs "region monitoring okay" and all the regions correctly. adding of the regions are done like so ``` double metres=20.0; CLLocationDistance dist=metres; CLLocationAccuracy acc=1.0; CLRegion *reg=[[CLRegion alloc] initCircularRegionWithCenter:coordinate radius:dist identifier:landmarkObj.landmarkName]; [locationManager startMonitoringForRegion:reg desiredAccuracy:acc]; ``` but the callbacks are all not triggered ``` - (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Entered" message:region.identifier delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil]; [alert show]; } - (void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Exited" message:region.identifier delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil]; [alert show]; } - (void)locationManager:(CLLocationManager *)manager didStartMonitoringForRegion:(CLRegion *)region { NSLog(@"started monitring for region: %@",region); } - (void) locationManager:(CLLocationManager *)manager monitoringDidFailForRegion:(CLRegion *)region withError:(NSError *)error { NSLog(@"%@",error); } ``` updating the location however, works fine. ``` [locationManager startUpdatingLocation]; ``` triggers the callback didUpdateToLocation as expected Update: used didUpdatToLocation to monitor for regions instead. still interested to know why this would not work though, looks like few have had success with region monitoring