CLLocationManager startUpdatingLocation不调用locationManager:didUpdateLocations:或locationManager:didFailWithError:

Question

我正在尝试使用CLLocationManager我的iOS项目中的框架来访问用户的位置,但是当我打电话时

[locationManager startUpdatingLocation]

既不locationManager:didUpdateLocations:或locationManager:didFailWithError:越来越调用.

//myViewController.h
@interface myViewController : UITableViewController <CLLocationManagerDelegate>
@end

//myViewController.m
@implementation myViewController{
    CLLocationManager *locationManager;
}

//edit
- (void)viewDidLoad
{
[super viewDidLoad];
locationManager = [[CLLocationManager alloc] init];
}
//finish edit

-(void)getLocation
{
    locationManager.delegate = self;
    locationManager.desiredAccuracy = kCLLocationAccuracyBest;
    [locationManager startUpdatingLocation];
}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
UIAlertView *errorAlert = [[UIAlertView alloc]
                           initWithTitle:@"Error" 
                                 message:@"Failed to Get Your Location"              
                                delegate:nil 
                       cancelButtonTitle:@"OK" 
                      otherButtonTitles:nil];
[errorAlert show];
}

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
    CLLocation *newLocation = locations[[locations count] -1];
    CLLocation *currentLocation = newLocation;
    NSString *longitude = [NSString stringWithFormat:@"%.8f", currentLocation.coordinate.longitude];
    NSString *latitude = [NSString stringWithFormat:@"%.8f", currentLocation.coordinate.latitude];

if (currentLocation != nil) {
   NSLog(@"latitude: %@", latitude);
   NSLog(@"longitude: @"%@", longitude);
}else {
    UIAlertView *errorAlert = [[UIAlertView alloc]
                               initWithTitle:@"Error" message:@"Failed to Get Your Location" 
                                                     delegate:nil 
                                            cancelButtonTitle:@"OK" 
                                            otherButtonTitles:nil];
    [errorAlert show];
}

}
@end

尽管在文档中说明了,但是没有调用委托方法:

"此方法立即返回.调用此方法会导致位置管理器获取初始位置修复(可能需要几秒钟)并通过调用其locationManager:didUpdateLocations:方法通知您的委托[...]除了实现该locationManager:didUpdateLocations:方法的委托对象之外,它还应该实施这种locationManager:didFailWithError:方法来应对潜在的错误."

不知道如何调试问题.

谢谢,

JA

Answer 1

只需在info.plist中添加它即可

NSLocationAlwaysUsageDescription ---我需要位置

NSLocationWhenInUseUsageDescription ---我需要位置

隐私 - 位置使用说明---我需要位置

  locationManager = [[CLLocationManager alloc] init];
  locationManager.delegate=self;
  locationManager.desiredAccuracy=kCLLocationAccuracyBest;
  locationManager.distanceFilter=kCLDistanceFilterNone;
  [locationManager requestWhenInUseAuthorization];
  [locationManager startMonitoringSignificantLocationChanges];
  [locationManager startUpdatingLocation];

现在它肯定会调用你的didUpdateToLocation.

有关详细信息,请单击此处

Answer 2

从iOS 8开始,位置服务的工作方式略有不同.

主要是,你需要一个键添加NSLocationWhenInUseUsageDescription到您的Info.plist文件,并添加说明为什么你的应用程序需要的位置,如"需要位置...".

请注意,您可能还需要检查iOS版本.只有iOS 8及更高版本才能让位置管理器收听该requestWhenInUseAuthorization呼叫.

以下链接显示更多详细信息:http: //nevan.net/2014/09/core-location-manager-changes-in-ios-8/

祝好运!

Answer 3

您需要检查是否在主线程上初始化CLLocationManager.在其他情况下,您将无法获得updateLocation事件.

我在Apple文档中找不到这样的信息,但无论如何它对我有用.

Answer 4

使用iOS 8.0,您需要先致电-[CLLocationManager requestWhenInUseAuthorization ]或-[CLLocationManager requestAlwaysAuthorization]首先要求用户授予您的应用程序使用该位置的权限.