Question

The CLLocationManager prompts an alert

“App name” Would you like to use your location

which offers two buttons, OK and Don’t allow. How to know which of the buttons has the user selected?

Answer 1

When you click on Don’t allow button

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
will be called with kCLAuthorizationStatusDenied exception. You can write your inside it.

Also refer :

kCLAuthorizationStatusNotDetermined = 0, // User has not yet made a choice with regards to this application
kCLAuthorizationStatusRestricted,        // This application is not authorized to use location services.  Due
                                             // to active restrictions on location services, the user cannot change
                                             // this status, and may not have personally denied authorization
kCLAuthorizationStatusDenied,            // User has explicitly denied authorization for this application, or
                                             // location services are disabled in Settings
kCLAuthorizationStatusAuthorized         // User has authorized this application to use location services

Example :

if user clicks on allow then

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation 
{
      [self refreshYourView];
}

If clicks on don’t allow

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error 
{
    if ([error code]== kCLAuthorizationStatusDenied) 
    {
         UIAlertView *alert;
    alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"User has clicked don't allow button." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [alert show];
        [alert release];

     }
}

EDIT

Alternate : you can display an alert that ask user to allow location access by enable location service from Settings.

You can use this on iOS 5.0 and later:

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs://"]];

in your app to open Settings app.