ios - CLLocationManager startUpdatingLocation 未调用 locationManager :didUpdateLocations: or locationManager:didFailWithError:

Question

我试图在我的 iOS 项目中使用 CLLocationManager 框架来访问用户的位置，但是当我调用时

[locationManager startUpdatingLocation]

locationManager:didUpdateLocations: 或 locationManager:didFailWithError: 都没有被调用。

//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

尽管文档中说了什么，但都没有调用委托(delegate)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: 方法通知您的代理 [. ..] 除了实现 locationManager:didUpdateLocations: 方法的委托(delegate)对象外，它还应该实现 locationManager:didFailWithError: 方法以响应潜在错误。"

不知道如何调试问题。

谢谢，

JA

Answer 1

只需将其添加到 info.plist 中

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

请注意，应更改“我需要位置”以描述您实际应用的设计用途。它在授权消息中传达给最终用户。 (感谢@devios1)

  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。

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