IOS 8 CLLocationManager问题(授权不起作用)

Question

#import "MyLocationViewController.h"
#define NSLog(FORMAT, ...) printf("%s\n", [[NSString stringWithFormat:FORMAT, ##__VA_ARGS__] UTF8String]);

@interface MyLocationViewController ()

@end

@implementation MyLocationViewController

{
    CLLocationManager *locationManager;
}

- (void)requestAlwaysAuthorization
{
    [locationManager requestAlwaysAuthorization];
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.
    self.mapView.showsUserLocation = YES;
    self.mapView.delegate = self;
    locationManager = [[CLLocationManager alloc] init];

}

- (IBAction)unwindToMap:(UIStoryboardSegue *)segue
{

}

- (IBAction)getCurrentLocation:(id)sender {
    locationManager.delegate = self;
    locationManager.desiredAccuracy = kCLLocationAccuracyBest;
    [locationManager startUpdatingLocation];
}

- (void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation
{
    MKCoordinateRegion mapRegion;
    mapRegion.center = mapView.userLocation.coordinate;
    mapRegion.span.latitudeDelta = 0.001;
    mapRegion.span.longitudeDelta = 0.001;




    CLLocationCoordinate2D location = userLocation.coordinate;
    float lat = location.latitude;
    float lng = location.longitude;

    NSDictionary *locationDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
                                        [NSNumber numberWithFloat:lat] , @"Latitude",
                                        [NSNumber numberWithFloat:lng], @"Longitude", nil];

    NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:
                                locationDictionary, @"Location_A",
                                nil];
    NSError *error;
    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dictionary options:NSJSONWritingPrettyPrinted error:&error];

    NSString *str = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
    NSLog(@"%@",str);



    if (mapView.userLocation != nil)
    {
        _longitudeLabel.text = [NSString stringWithFormat:@"%.8f", mapView.userLocation.coordinate.longitude];
        _latitudeLabel.text = [NSString stringWithFormat:@"%.8f", mapView.userLocation.coordinate.latitude];
    }

    [mapView setRegion:mapRegion animated: YES];

}


- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

这是我的代码.

现在,我知道我需要使用NSLocationAlwaysUsageDescription键编辑我的info.plist文件(我做了),并为描述添加了一个字符串.

但是,我在实现授权部分时遇到问题,因为错误仍然如此:

Trying to start MapKit location updates without prompting for location authorization. Must call -[CLLocationManager requestWhenInUseAuthorization] or -[CLLocationManager requestAlwaysAuthorization] first.

我已经为CLLocationManager阅读了Apple IOS 8文档,但不知怎的,我的代码无法正常工作.

有人可以帮助我,以便通过查看我需要修改的代码中的哪些内容来使上述错误消息消失,以便它可以工作吗？

谢谢!

Answer 1

你不应该在转MKMapView的showsUserLocation用户已授权您的应用程序使用位置服务之前.

您可以实现CLLocationManagerDelegate的locationManager:didChangeAuthorizationStatus:方法和打开showsUserLocation那里就像这样:

- (void)locationManager:(CLLocationManager *)manager didChangeAuthorizationStatus:(CLAuthorizationStatus)status {  
    if (status == kCLAuthorizationStatusAuthorizedAlways || status == kCLAuthorizationStatusAuthorizedWhenInUse) {
        self.mapView.showsUserLocation = YES;
    }
}