I did this in an application I'm developing. The timers don't work when the app is in the background but the app is constantly receiving the location updates. I read somewhere in the documentation (i can't seem to find it now, i'll post an update when i do) that a method can be called only on an active run loop when the app is in the background. The app delegate has an active run loop even in the bg so you dont need to create your own to make this work. [Im not sure if this is the correct explanation but thats how I understood from what i read]

首先，在应用的info.plist中添加关键UIBackgroundModes的location对象。现在，你需要做的是启动位置更新在你的应用程序的任何地方:

    CLLocationManager locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self;//or whatever class you have for managing location
    [locationManager startUpdatingLocation];

Next, write a method to handle the location updates, say -(void)didUpdateToLocation:(CLLocation*)location, in the app delegate. Then implement the method locationManager:didUpdateLocation:fromLocation of CLLocationManagerDelegate in the class in which you started the location manager (since we set the location manager delegate to 'self'). Inside this method you need to check if the time interval after which you have to handle the location updates has elapsed. You can do this by saving the current time every time. If that time has elapsed, call the method UpdateLocation from your app delegate:

NSDate *newLocationTimestamp = newLocation.timestamp;
NSDate *lastLocationUpdateTiemstamp;

int locationUpdateInterval = 300;//5 mins

NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
if (userDefaults) {

        lastLocationUpdateTiemstamp = [userDefaults objectForKey:kLastLocationUpdateTimestamp];

        if (!([newLocationTimestamp timeIntervalSinceDate:lastLocationUpdateTiemstamp] < locationUpdateInterval)) {
            //NSLog(@"New Location: %@", newLocation);
            [(AppDelegate*)[UIApplication sharedApplication].delegate didUpdateToLocation:newLocation];
            [userDefaults setObject:newLocationTimestamp forKey:kLastLocationUpdateTimestamp];
        }
    }
}

这将每5分钟调用你的方法，即使你的应用程序是在后台。 Imp:这个实现耗尽电池，如果你的位置数据的准确性不是关键，你应该使用[locationManager startMonitoringSignificantLocationChanges]

在将此添加到应用程序之前，请阅读位置感知编程指南

I did this in an application I'm developing. The timers don't work when the app is in the background but the app is constantly receiving the location updates. I read somewhere in the documentation (i can't seem to find it now, i'll post an update when i do) that a method can be called only on an active run loop when the app is in the background. The app delegate has an active run loop even in the bg so you dont need to create your own to make this work. [Im not sure if this is the correct explanation but thats how I understood from what i read]

首先，在应用的info.plist中添加关键UIBackgroundModes的location对象。现在，你需要做的是启动位置更新在你的应用程序的任何地方:

    CLLocationManager locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self;//or whatever class you have for managing location
    [locationManager startUpdatingLocation];

Next, write a method to handle the location updates, say -(void)didUpdateToLocation:(CLLocation*)location, in the app delegate. Then implement the method locationManager:didUpdateLocation:fromLocation of CLLocationManagerDelegate in the class in which you started the location manager (since we set the location manager delegate to 'self'). Inside this method you need to check if the time interval after which you have to handle the location updates has elapsed. You can do this by saving the current time every time. If that time has elapsed, call the method UpdateLocation from your app delegate:

NSDate *newLocationTimestamp = newLocation.timestamp;
NSDate *lastLocationUpdateTiemstamp;

int locationUpdateInterval = 300;//5 mins

NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
if (userDefaults) {

        lastLocationUpdateTiemstamp = [userDefaults objectForKey:kLastLocationUpdateTimestamp];

        if (!([newLocationTimestamp timeIntervalSinceDate:lastLocationUpdateTiemstamp] < locationUpdateInterval)) {
            //NSLog(@"New Location: %@", newLocation);
            [(AppDelegate*)[UIApplication sharedApplication].delegate didUpdateToLocation:newLocation];
            [userDefaults setObject:newLocationTimestamp forKey:kLastLocationUpdateTimestamp];
        }
    }
}

这将每5分钟调用你的方法，即使你的应用程序是在后台。 Imp:这个实现耗尽电池，如果你的位置数据的准确性不是关键，你应该使用[locationManager startMonitoringSignificantLocationChanges]

在将此添加到应用程序之前，请阅读位置感知编程指南

在iOS 9和watchOS 2.0中，CLLocationManager上有一个新方法，可以让你请求当前位置:CLLocationManager:requestLocation()。这立即完成，然后将位置返回给CLLocationManager委托。

你现在可以使用NSTimer每分钟用这个方法请求一个位置，而不必使用startUpdatingLocation和stopUpdatingLocation方法。

然而，如果你想要根据上次位置X米的变化来捕获位置，只需要设置CLLocationManger的distanceFilter属性并调用startUpdatingLocation()。

现在iOS6已经发布了，永远运行位置服务的最好方法是……

- (void)applicationWillResignActive:(UIApplication *)application
{
/*
 Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
 Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
 */

NSLog(@"to background");

app.isInBackground = TRUE;

UIApplication *app = [UIApplication sharedApplication];

// Request permission to run in the background. Provide an
// expiration handler in case the task runs long.
NSAssert(bgTask == UIBackgroundTaskInvalid, nil);

bgTask = [app beginBackgroundTaskWithExpirationHandler:^{
    // Synchronize the cleanup call on the main thread in case
    // the task actually finishes at around the same time.
    dispatch_async(dispatch_get_main_queue(), ^{

        if (bgTask != UIBackgroundTaskInvalid)
        {
            [app endBackgroundTask:bgTask];
            bgTask = UIBackgroundTaskInvalid;
        }
    });
}];

// Start the long-running task and return immediately.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

    // Do the work associated with the task.

    locationManager.distanceFilter = 100;
    locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters;
    [locationManager startMonitoringSignificantLocationChanges];
    [locationManager startUpdatingLocation];

    NSLog(@"App staus: applicationDidEnterBackground");
    // Synchronize the cleanup call on the main thread in case
    // the expiration handler is fired at the same time.
    dispatch_async(dispatch_get_main_queue(), ^{
        if (bgTask != UIBackgroundTaskInvalid)
        {
            [app endBackgroundTask:bgTask];
            bgTask = UIBackgroundTaskInvalid;
        }
    });
});

NSLog(@"backgroundTimeRemaining: %.0f", [[UIApplication sharedApplication] backgroundTimeRemaining]);

}

就像这样测试:

我打开应用程序，进入后台，几分钟后开车。然后我回家1小时，再次开始移动(没有再次打开应用程序)。重新开始定位。然后停了两个小时，又重新开始。一切都好了……

不要忘记在iOS6中使用新的位置服务

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{   
    CLLocation *loc = [locations lastObject];

    // Lat/Lon
    float latitudeMe = loc.coordinate.latitude;
    float longitudeMe = loc.coordinate.longitude;
}

if ([self.locationManager respondsToSelector:@selector(setAllowsBackgroundLocationUpdates:)]) {
    [self.locationManager setAllowsBackgroundLocationUpdates:YES];
}

自iOS 9以来，这是后台位置跟踪所需要的。

似乎stopUpdatingLocation是什么触发后台看门狗定时器，所以我在didUpdateLocation替换它:

     [self.locationManager setDesiredAccuracy:kCLLocationAccuracyThreeKilometers];
     [self.locationManager setDistanceFilter:99999];

这似乎有效地关闭了GPS。然后，背景NSTimer的选择器变成:

- (void) changeAccuracy {
[self.locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
[self.locationManager setDistanceFilter:kCLDistanceFilterNone];
}

我所做的是每隔几分钟定期切换精度以获得高精度坐标，因为locationManager没有停止，backgroundtimerremain保持在其最大值。这将我的设备上的电池消耗从每小时~10%(在后台使用恒定的kCLLocationAccuracyBest)降低到每小时~2%