IPhone : Location manager is not working

Please don't mark it as duplicate because I took help from others posted answer in site. But still I faced some issues. Location manager delegate not get called even in real device also. And also it's not asking for the permission. Below is my code.

- (IBAction)getUserLocationAction:(id)sender
{
    if([CLLocationManager locationServicesEnabled])
    {
        if(!locationManager)
            locationManager = [[CLLocationManager alloc] init];

        [locationManager setDelegate:self];
        [locationManager setDesiredAccuracy:kCLLocationAccuracyBest];

        if ([locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]) {
            [locationManager requestWhenInUseAuthorization];
        }

        [locationManager startUpdatingLocation];
        //[locationManager startMonitoringSignificantLocationChanges];
    }
    else
    {
        NSLog(@"Location service is not enabled");
    }
}


#pragma mark - Location Manager Delegate- 

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
    NSLog(@"%@", locations);
    userLocation = [locations lastObject];
    NSLog(@"User Current Locatiion\nLat: %+.6f\nLong: %+.6f", [userLocation coordinate].latitude, [userLocation coordinate].longitude);

   [locationManager stopUpdatingLocation];
   //[locationManager stopMonitoringSignificantLocationChanges];
}



- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
    NSLog(@"Error: %@", [error localizedDescription]);
}

I also add the below two key in my .plist file

<key>NSLocationWhenInUseUsageDescription</key>
<string>This app want to use your location</string>
<key>NSLocationAlwaysUsageDescription</key>
<string>This app want to use your location</string>

I am not sure where I am doing wrong. Please help me.