[iOS]捕获用户位置:说明

Question

我有一个应用程序，捕获用户的位置，并将此信息发送到我的服务器。

我用以下命令启动了LocationManager服务：

- (CLLocationManager *)locationManager {
    if (_locationManager == nil) {
        _locationManager = [[CLLocationManager alloc] init];
        _locationManager.delegate = self;
        isUpdatingLocation = NO;
    }
    return _locationManager; 
}

-(void) startLookingForLocation{

    [self locationManager].desiredAccuracy = kCLLocationAccuracyBest;
    [self locationManager].distanceFilter = 250;

    if([[self locationManager]respondsToSelector:@selector(setPausesLocationUpdatesAutomatically:)])
        [[self locationManager] setPausesLocationUpdatesAutomatically:YES];

    if([[self locationManager]respondsToSelector:@selector(setActivityType:) ])
        [[self locationManager] setActivityType:CLActivityTypeFitness];

    [[self locationManager] startUpdatingLocation];
    [[self locationManager] startUpdatingHeading];

    isUpdatingLocation = YES;
}

并通过以下方式停止它：

-(void) stopLookingForLocation{

    [[self locationManager] stopUpdatingLocation];
    [[self locationManager] stopUpdatingHeading];

    isUpdatingLocation = NO;

}

因此，当我检测到用户位置发生变化时：

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {

    [self setCurrentLocation:newLocation];

    BOOL isInBackground = NO;
    if ([UIApplication sharedApplication].applicationState == UIApplicationStateBackground)
    {
        isInBackground = YES;
    }

    if (isInBackground)
    {
        UIBackgroundTaskIdentifier bgTask = [[UIApplication sharedApplication]
                  beginBackgroundTaskWithExpirationHandler:
                  ^{
                      [[UIApplication sharedApplication] endBackgroundTask:bgTask];
                  }];

        // Send user-location to my server

        if (bgTask != UIBackgroundTaskInvalid)
        {
            [[UIApplication sharedApplication] endBackgroundTask:bgTask];
            bgTask = UIBackgroundTaskInvalid;
        }
    }
    else
    {
        // Send user-location to my server
    }

}

一切工作正常。(我想)。

当应用程序进入后台模式时，我在appDelegate - (void)applicationDidEnterBackground:(UIApplication *)应用程序{ locationManager startMonitoringSignificantLocationChanges；}中调用此方法。

当app返回前台时：

- (void)applicationDidBecomeActive:(UIApplication *)application
{
    [locationManager stopMonitoringSignificantLocationChanges];
}

但我有一些疑问。这样，如果应用程序处于关闭状态，我的应用程序会继续与服务器通信位置吗？

当我处于后台或前台状态时，如何才能发送位置？

编辑:我还设置了：

UIBackgroundModes位置

Answer 1

没有这个代码的需要，这将激活你的应用程序在后台很少的时间，你必须提到项目的info.plist中所需的后台模式，该值应为位置更新的应用程序注册。

只需在info.plist中设置UIBackgroundModes位置，它就可以在后台运行，这可能会对您有所帮助。

//In app deligate 

#pragma mark -
#pragma mark  GPS Service

//========== start GPS SERVICE ===========
-(void)startGpsService
{

    locationManager=[[CLLocationManager alloc] init];
    locationManager.delegate=self;
    locationManager.desiredAccuracy=kCLLocationAccuracyBest;
    locationManager.distanceFilter=10.0;
    [locationManager startUpdatingLocation];
    [self performSelectorInBackground:@selector(sendDataToServer) withObject:nil];
}

#pragma mark -
#pragma mark CLLocation Manager Delegates

- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
       fromLocation:(CLLocation *)oldLocation
{
      [self performSelectorInBackground:@selector(sendDataToServer) withObject:nil];

}

- (void)applicationDidEnterBackground:(UIApplication *)application
{
    // No need to do any thing 
   /* UIApplication *app = [UIApplication sharedApplication];
      UIBackgroundTaskIdentifier bgTask = 0;
      bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
      [app endBackgroundTask:bgTask];
       }];
*/
}