Question

Is it possible to start / stop location updates from the UI of the iphone? All I need from the app is to show me my location unless I click “stop” and then “start” again.

I can’t seem to be able to do that…I have my location displayed properly, and I also created two IBButtons and created a function for each of them, however, my app crashes when I click on each one of those buttons. I placed those functions under the viewcontroller.m.

I am kind of new to this, so any help would be appreciated. Thanks!

• (IBAction)startUpdating: (CLLocation *)location
  {

  [location startUpdatingLocation];

  }

• (IBAction)stopUpdating: (CLLocation *)location
  {

  [location stopUpdatingLocation];

  }

Answer 1

start/stopUpdatingLocation are CLLocationManager instance methods, rather than CLLocation instance methods… so create a CLLocationManager instance.

.h

@interface someClass:somesuperclass{
CLLocationManager * locationManager;
BOOL updating;
}
-(IBAction)toggleUpdating:(id)sender;

@end

.m somewhere in the view load/ or init cycle:

-(void)viewDidLoad{
  [super viewDidLoad];
  locationManager = [[CLLocationManager alloc] init];
 }
 -(void)viewDidUnload{
 [locationManager stopUpdatingLocation];
 [locationManager release];
 [super viewDidUnload];
 }

-(IBAction)toggleUpdating:(id)sender
{
     if(!updating)
     {
         [locationManager startUpdatingLocation];
     }else{
         [locationManager stopUpdatingLocation];
     }
     updating = !updating;
}

also your action above will never work, because the thing after a colon in an action will be the object that sent the action, a UIButton in your case.