問題描述：   在iOS8之前，app第一次開始定位服務時，系統會彈出一個提示框來讓用戶選擇是否允許使用定位信息。但iOS8後，app將不會出現這個彈窗   。第一次運行之後，在設置->隱私->定位服務中，你的app沒有任何設置，既不是“永不”，也不是“始終”。   代碼如下：   復制代碼 #import "XYZFirstViewController.h"   @interface XYZFirstViewController () - (IBAction)LocateButtonClick:(id)sender; @end   @implementation XYZFirstViewController   - (void)viewDidLoad {     [super viewDidLoad];     // Do any additional setup after loading the view.          [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(startLocate) name:@"startLocateNotification"    object:nil];     _locationManager=[[CLLocationManager alloc] init];     _locationManager.delegate=self;     _locationManager.desiredAccuracy=kCLLocationAccuracyBest;     _locationManager.distanceFilter=1000.0f;     _mapView.mapType=MKMapTypeStandard;     _mapView.delegate=self;      }   - (void)didReceiveMemoryWarning {     [super didReceiveMemoryWarning];     // Dispose of any resources that can be recreated. }   -(void) viewWillAppear:(BOOL)animated{     [super viewWillAppear:animated];     [_locationManager startUpdatingLocation]; }   -(void) viewWillDisappear:(BOOL)animated {     [super viewWillDisappear:animated];     [_locationManager stopUpdatingLocation]; }     -(void) locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {     CLLocation *currentLocation=[locations lastObject];     _currentLocation=currentLocation;     self.currentLocationLabel.text=[NSString stringWithFormat:@"%3.5f,%3.5f,%3.5f",    currentLocation.coordinate.longitude,currentLocation.coordinate.latitude,currentLocation.altitude];     MKCoordinateRegion region=MKCoordinateRegionMakeWithDistance(currentLocation.coordinate, 1000, 1000);     [_mapView setRegion:region animated:YES];     MKPointAnnotation *point=[[MKPointAnnotation alloc] init];     point.coordinate=_currentLocation.coordinate;     point.title=@"my location";     [_mapView addAnnotation:point]; }   -(void) locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {     NSLog(@"error:%@",error); }   /* #pragma mark - Navigation   // In a storyboard-based application, you will often want to do a little preparation before navigation - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {     // Get the new view controller using [segue destinationViewController].     // Pass the selected object to the new view controller. } */   - (IBAction)LocateButtonClick:(id)sender {     [[NSNotificationCenter defaultCenter] postNotificationName:@"startLocateNotification" object:self ]; }   -(void) startLocate {     CLGeocoder *geocoder=[[CLGeocoder alloc]init];     [geocoder reverseGeocodeLocation:_currentLocation completionHandler:^(NSArray *placeMarks, NSError *error)      {         if([placeMarks count]>0)         {             NSLog(@"%@",placeMarks);             CLPlacemark *placeMark=placeMarks[0];             NSDictionary *addressDictonary=placeMark.addressDictionary;             _currentAddressLabel.text=[NSString stringWithFormat:@"%@,%@,%@",[addressDictonary objectForKey:(NSString *)   kABPersonAddressStateKey],[addressDictonary objectForKey:(NSString *)kABPersonAddressCityKey],[addressDictonary    objectForKey:(NSString *) kABPersonAddressStreetKey] ];         }      }];                } @end 復制代碼     解決方案：   以上代碼在iOS8之後需要手動調用CLLocationManager對象的requestAlwaysAuthorization／   requestWhenInUseAuthorization方法。 調用該方法需要在Info.plist中設置   NSLocationAlwaysUsageDescription/NSLocationWhenInUseUsageDescription的值，這個值會顯示在系統提示框中。   代碼如下：   -(void) viewWillAppear:(BOOL)animated{     [super viewWillAppear:animated];     [_locationManager requestWhenInUseAuthorization];     [_locationManager startUpdatingLocation]; }