CODEWITHSUNDEEP
iphonecllocationmanager
lilzz
lilzz

Reputation: 5413

Inconsistent locationManager didupdatetolocation on Iphone

@implementation MyLocation


SYNTHESIZE_SINGLETON_FOR_CLASS(MyLocation);

@synthesize delegate, locationManager;

- (id) init 
{
    self = [super init];
    if (self != nil) 
    {       
        self.locationManager = [[[CLLocationManager alloc] init] autorelease];

        self.locationManager.delegate = self;
    }
    return self;
}


- (void) timeoutHandler:(NSTimer *)_timer
{

    timer = nil;

    [self update_location];
}

-(void) update_location
{
    hasLocation=NO;

    [locationManager startUpdatingLocation];

    timer = [NSTimer scheduledTimerWithTimeInterval: 3.0
                                         target: self
                                       selector: @selector(timeoutHandler:)
                                       userInfo: nil
                                        repeats: NO
         ];
}


- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
    NSLog(@"location ready");
    if(timer != nil) {
        [timer invalidate];
        timer = nil;
    }
    hasLocation = YES;

    [[NSNotificationCenter defaultCenter] postNotificationName:@"location_ready"                         object:nil]; 


    if (debug_switch)
        NSLog(@" Delegate function, Getting new location from locationManager from Mylocation.m");


    _coordinate = newLocation.coordinate;

    source_lat=_coordinate.latitude;
    source_lng=_coordinate.longitude;

    //TRACE(@"new location: %f %f", _coordinate.latitude, _coordinate.longitude);
    //[delegate locationUpdate:newLocation.coordinate];

}

The first time, I run the update_location routine, the location manager quickly jump to callback routine of didupdatetolocation. No Problem

However, next time I call the update_location function again, the callback didupdatetolocation never entered. Why such discrepancy? why the callback isn't entered?

Upvotes: 0

Views: 1026

Answers (2)

barley
barley

Reputation: 4473

Your usage of LocationManager is incorrect. You only need to call startUpdatingLocation once, and the callback is invoked repeatedly whenever there is big enough change.

As of why with your observation, probably there was no significant change to invoke callback.

Upvotes: 2

bryanmac
bryanmac

Reputation: 39296

Why create a timer that keeps calling CLLocationManager startUpdatingLocation?

The CLLocationManager is typically used by setting yourself as the delegate. start it and then you get callbacks when the location changes.

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation

Here's a tutorial showing how to use it:

http://mobileorchard.com/hello-there-a-corelocation-tutorial/

Upvotes: 0

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