iOS重大位置更改和didUpdateLocations

Question

I'm obviously missing something basic here. I am busy with an app that monitors significant location changes. I run the app. and then close it completely, didUpdateLocations in my delegate is fired when it's necessary, but my location is nil.

- (void)locationManager:(CLLocationManager *)manager
     didUpdateLocations:(NSArray *)locations {
    NSLog(@"didUpdateLocations: %@", [locations lastObject]);
    CLLocation* location = [locations lastObject];
    NSLog(@"latitude %+.6f, longitude %+.6f\n",
          location.coordinate.latitude,
          location.coordinate.longitude); 
}

any thoughts/help?

Thanks

Answer 1

Add this to your plist

<key>NSLocationAlwaysUsageDescription</key>
<string></string>
<key>NSLocationWhenInUseUsageDescription</key>
<string></string>

And this code

#define IS_OS_8_OR_LATER ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)


    if(IS_OS_8_OR_LATER) {
            [locationManager requestAlwaysAuthorization];
        }

Answer 2

In iOS 9 this what I did, in plist I added:

<key>NSLocationAlwaysUsageDescription</key>
<string>Location is required to find out where you are</string>

In class you use Core Location Manager

 - (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {

     BOOL isInBackground = NO;
    if ([UIApplication sharedApplication].applicationState == UIApplicationStateBackground)
    {
        isInBackground = YES;
    }

    if (isInBackground) {
        // Do something while in the background
    } else {
        // while in use
    }

 }

And in the delegate I start monitoring significant location services

- (void)applicationDidEnterBackground:(UIApplication *)application {
    NSLog(@"App going to the background");
    [_locationManager startMonitoringSignificantLocationChanges];
}