Question

我有一个应用程序，每隔2分钟和25米的行程在后台获取位置更新。我的问题是，虽然位置跟踪工作正常，但它严重耗尽了我的电池。 24小时内的电池使用率为30％，而下一个最接近的应用程序为14％。是否有一些技巧可以降低我的应用程序的电池使用量，同时保持我的准确性和位置更新的时间段？

由于调用didUpdateLocations的频率，它可能会耗尽电池吗？或者可能是我在后台与每个位置更新的Web服务进行通信？我真的不知道如何提高电池使用率，非常感谢任何帮助！

以下是我在AppDelegate中的代码，用于获取位置并向服务器发送更新：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
     self.locationManager = [CLLocationManager new];
    [self.locationManager setDelegate:self];
    if ([self.locationManager respondsToSelector:@selector(requestAlwaysAuthorization)]) {
        [self.locationManager requestAlwaysAuthorization];
    }
    [self.locationManager startUpdatingLocation];
    [self.locationManager startMonitoringSignificantLocationChanges];

    [self initializeRegionMonitoring];
}

-(void) initializeRegionMonitoring {
    self.locationManager = [[CLLocationManager alloc] init];
    self.locationManager.delegate = self;

    // notify changes when the device has moved x meters
    self.locationManager.distanceFilter = 25; // or set to 20 meters
    self.locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters;
    [self.locationManager startUpdatingLocation];
    [self.locationManager startMonitoringSignificantLocationChanges];
}

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSDate *lastDate = [defaults objectForKey:@"lastSavedDate"];

    if ([[NSDate date] timeIntervalSinceDate:lastDate] < 120) {
        NSLog(@"LAST SAVE TIME LESS THAN 2 MINUTES");
        return;
    }

    [self saveLocation];    

    //tell the centralManager that you want to deferred this updatedLocation
    if (isBackgroundMode && !_deferringUpdates)
    {
        NSLog(@"THIS IS GETTING CALLED EVERY TIME");
        _deferringUpdates = YES;
        [self.locationManager allowDeferredLocationUpdatesUntilTraveled:CLLocationDistanceMax timeout:120];
    }
}

- (void) locationManager:(CLLocationManager *)manager didFinishDeferredUpdatesWithError:(NSError *)error {

    _deferringUpdates = NO;
}

-(void) saveLocation {
    // This code saves location data to a web service
}

- (void)applicationWillResignActive:(UIApplication *)application {
    isBackgroundMode = YES;

    [self.locationManager stopUpdatingLocation];
    [self.locationManager setDesiredAccuracy:kCLLocationAccuracyNearestTenMeters];
    [self.locationManager setDistanceFilter:25];
    self.locationManager.pausesLocationUpdatesAutomatically = NO;
    self.locationManager.activityType = CLActivityTypeAutomotiveNavigation;
    [self.locationManager startUpdatingLocation];
}


-(BOOL)application:(UIApplication *)application willFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    [[UIApplication sharedApplication] setMinimumBackgroundFetchInterval:UIApplicationBackgroundFetchIntervalMinimum];
    return true;
}

-(void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {

    [self saveLocation];

   completionHandler(UIBackgroundFetchResultNewData);
    NSLog(@"Fetch completed");
}

Answer 1

[self.locationManager setDesiredAccuracy:kCLLocationAccuracyNearestTenMeters];    
[self.locationManager setDistanceFilter:25];

将这些属性更改为不太准确。您可以节省大量电池。这些配置取决于它是什么类型的应用程序。如果它是某种卡路里燃烧应用程序，它可能是非常准确的。您每2分钟更新一次，因此应将其设置为具有某个阈值的时间覆盖的近似距离的平均值。

Answer 2

self.locationManager.pausesLocationUpdatesAutomatically=YES;
//monitor locations for significant location change
[self.locationManager startMonitoringSignificantLocationChanges];

如果您的应用确实不需要用户准确定位，您可以尝试使用更多内存优化方式进行重大位置更改，但最终取决于具体情况更重要，即高位置精度或电池用法。我已经对这种方法进行了重大测试，通常每4-5分钟或500米更新一次，以最早者为准。

iOS：使用太多电池的后台定位应用

2 个答案: