ios - HealthKit 后台转换一分钟运行多次

Question

我已经在委托(delegate)的 didFinishLaunching 方法中注册了四种类型的 HealthKit 数据的后台传送。数据类型为步数、 sleep 、锻炼和energyConsumed。

我注意到我对这些数据类型的观察者查询在某些情况下每秒被 HealthKit/iOS 调用很多次。以下是调用 sleep 观察器查询的一些设备日志中的示例:

2017/03/27 07:21:58:821 Delegate - steps observer query received new data

2017/03/27 07:21:58:894 Delegate - steps observer query received new data

2017/03/27 07:21:58:936 Delegate - steps observer query received new data

2017/03/27 07:21:58:973 Delegate - steps observer query received new data

2017/03/27 07:21:58:993 Delegate - steps observer query received new data

2017/03/27 07:21:59:000 Delegate - steps observer query received new data

2017/03/27 07:21:59:024 Delegate - steps observer query received new data

2017/03/27 07:21:59:130 Delegate - steps observer query received new data

2017/03/27 07:21:59:145 Delegate - steps observer query received new data

2017/03/27 07:21:59:156 Delegate - steps observer query received new data

2017/03/27 07:21:59:169 Delegate - steps observer query received new data

2017/03/27 07:21:59:309 Delegate - steps observer query received new data

2017/03/27 07:21:59:328 Delegate - steps observer query received new data

2017/03/27 07:21:59:346 Delegate - steps observer query received new data

2017/03/27 07:21:59:404 Delegate - steps observer query received new data

2017/03/27 07:21:59:480 Delegate - steps observer query received new data

2017/03/27 07:21:59:499 Delegate - steps observer query received new data

2017/03/27 07:21:59:520 Delegate - steps observer query received new data

2017/03/27 07:21:59:547 Delegate - steps observer query received new data

2017/03/27 07:21:59:561 Delegate - steps observer query received new data

2017/03/27 07:21:59:571 Delegate - steps observer query received new data

2017/03/27 07:21:59:583 Delegate - steps observer query received new data

这是我的应用委托(delegate)中创建此日志的代码:

- (void)setUpStepsObserverQuery {

__weak typeof(self) weakSelf = self;

HKSampleType *sampleType = [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierStepCount];
HKObserverQuery *query = [[HKObserverQuery alloc] initWithSampleType:sampleType predicate:nil updateHandler:^(HKObserverQuery *query, HKObserverQueryCompletionHandler completionHandler, NSError *error) {

    if (completionHandler) {
        completionHandler();
    }
           
    if (error) {
        DDLogDebug(@"App Delegate - An error occured while setting up the stepCount observer: %@", error.localizedDescription);
    
    } else {
        DDLogDebug(@"Delegate - steps observer query received new data");
        
        weakSelf.activityTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{
            [weakSelf endBackgroundTask:weakSelf.activityTask];
        }];

// At this point I run an anchor query to check if there really is new data, and if there is I go ahead and send the new HealthKit data to our server.

    }];

    [_healthStore executeQuery:query]; // _healthStore is a shared instance of HKHealthStore I created earlier
}

这就是我为步数数据启用后台传送的方式。我在 didFinishLaunching 中调用了这个方法，它调用了我在上面分享的一个片段，setUpStepsObserverQuery

if ([defaults boolForKey:HK_ACTIVITY_SYNC]) {
    [self setUpStepsObserverQuery];
    [_healthStore enableBackgroundDeliveryForType:[HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierStepCount]
                                        frequency:HKUpdateFrequencyImmediate
                                   withCompletion:^(BOOL success, NSError * _Nullable error) {
                                       DDLogDebug(@"Delegate - enabled step count background updates");
                                   }];

对于为什么 HealthKit 会在同一分钟内多次调用我的观察者查询有什么想法吗？

Answer 1

这是因为每次您的观察查询被调用时，您的 didFinishLaunching 函数也会被调用，并且 enableBackgroundDeliveryForType 也会被调用，每次启用时，查询都会被调用执行。

您必须检查是否启用了后台传送，不要再次启用它!