如何检测用户选择不允许MKMapView for iphone

Question

I have created a application which uses mapview. For maps I used MKMapKit library. Everything works fine when user selects "Allow" button on alert window. But I want to detect when user selects "Don't Allow". I found a delegate which most of the developers used

(void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error

but the delegate does not get called.

Maybe I am missing something. In my header (.h) file I have implemented MKMapViewDelegate . Is there anything else I need to do?

Do I need to add some extra classes like CLLocationManager or else.

Thanks,

Answer 1

In order to monitor the changes in the authorization status for the location services you need to implement the CLLocationManagerDelegate method locationManager:didChangeAuthorizationStatus: obtaining something like

-(void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status {

    if (status == kCLAuthorizationStatusDenied) {
        // permission denied
    }
    else if (status == kCLAuthorizationStatusAuthorized) {
        // permission granted
    }
}

For a complete list of the possible authorization statuses and their description you can check out the official documentation of CLAuthorizationStatus .

EDIT

You probably have already your instance of CLLocationManager , let's call it locationManager . Then in order to implement your delegate you conform your class to the CLLocationManagerDelegate protocol (you can declare it in the header of class -- this is not mandatory but it will provide you some static checking facilities) and assign it to the delegate property of locationManager like follows:

locationManager.delegate = self; //assuming that self is gonna be the delegate

If you did everything as explained your controller will be called at every authorization change, as stated by the documentation:

this method is called whenever the application's ability to use location services changes.

Answer 2

Can you try this:

if(![CLLocationManager locationServicesEnabled])
{
    // alert location services denied
}

Answer 3

// in appdelegate put thecode

-(void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status {

    if (status == kCLAuthorizationStatusDenied)
     {
        //location denied, handle accordingly
         NSLog(@"Dont allow");

    }
    else if (status == kCLAuthorizationStatusAuthorized)
    {
        NSLog(@"Allow");
        //hooray! begin startTracking
    }

}

// Wheneever you check

- (IBAction)showMapBtnPressed:(id)sender {

    if([CLLocationManager authorizationStatus] == kCLAuthorizationStatusDenied)
    {
        NSLog(@"Dont allow");

    }else
    {
        NSLog(@" allow");
    }


}