调度组未通知

Question

我在另一个应用程序中有这个相同的代码，它可以正常工作，现在在这个应用程序中，调度组没有通知，我的处理程序也没有被调用？我搞不清这两个应用程序之间的区别，因为代码是相同的？

func getHeartRateMaxFromWorkouts(workouts: [HKWorkout], handler: @escaping (careerMaxHeartRatePerWorkoutAsCustomHistoricalSample, careerAverageHeartRatePerWorkoutAsCustomHistoricalSample) -> Void) {
let workoutsReversed = workouts.reversed()
guard let heartRateType:HKQuantityType = HKQuantityType.quantityType(forIdentifier: HKQuantityTypeIdentifier.heartRate) else { return }
let heartRateUnit:HKUnit = HKUnit(from: "count/min")
var heartRateMaxArrayAsCustomHistoricalSample = [CustomHistoricalSample]()
var heartRateAvgArrayAsCustomHistoricalSample = [CustomHistoricalSample]()
//DispatchGroup needed since making async call per workout and need notified when all calls are done
let dispatchGroup = DispatchGroup()
for workout in workoutsReversed {
//predicate
let startDate = workout.startDate
let endDate = workout.endDate
let predicate = HKQuery.predicateForSamples(withStart: startDate, end: endDate, options: .strictStartDate)
//descriptor
let sortDescriptors = [
NSSortDescriptor(key: HKSampleSortIdentifierEndDate, ascending: true) //Changed this to false so that HRR and MCS would calculate, always check this if not getting these values
]
dispatchGroup.enter()
let heartRateQuery = HKSampleQuery(sampleType: heartRateType,
predicate: predicate,
limit: (HKObjectQueryNoLimit),
sortDescriptors: sortDescriptors)
{ (query:HKSampleQuery, results:[HKSample]?, error:Error?) -> Void in
guard error == nil else { print("get heart rate error"); return }
guard let unwrappedResults = results as? [HKQuantitySample] else { print("get heart rate error"); return}
let heartRatesAsDouble = unwrappedResults.map {$0.quantity.doubleValue(for: heartRateUnit)}
guard let max = heartRatesAsDouble.max() else { return }
let maxAsCustomHistoricalSample = CustomHistoricalSample(value: max, date: workout.startDate)
heartRateMaxArrayAsCustomHistoricalSample.append(maxAsCustomHistoricalSample)
let average = heartRatesAsDouble.average
let averageAsCustomHistoricalSample = CustomHistoricalSample(value: average, date: workout.startDate)
heartRateAvgArrayAsCustomHistoricalSample.append(averageAsCustomHistoricalSample)
dispatchGroup.leave()
}
healthStore.execute(heartRateQuery)
} //End of for workout loop
dispatchGroup.notify(queue: .main) {
//Need to sort by date since the dates come back jumbled 
let sortedReversedHeartRateMaxArrayAsCustomHistoricalSampple = heartRateMaxArrayAsCustomHistoricalSample.sorted { $0.date > $1.date }.reversed() as [CustomHistoricalSample]
let sortedReversedHeartRateAverageArrayAsCustomHistoricalSampple = heartRateAvgArrayAsCustomHistoricalSample.sorted { $0.date > $1.date }.reversed() as [CustomHistoricalSample]
print("handler called = (sortedReversedHeartRateMaxArrayAsCustomHistoricalSampple.count)")
handler(sortedReversedHeartRateMaxArrayAsCustomHistoricalSampple, sortedReversedHeartRateAverageArrayAsCustomHistoricalSampple)
}

} //End getHeartRateMaxFromWorkouts

Answer 1

将leaf置于回调的顶部是一个很好的做法

guard error == nil else { print("get heart rate error");  dispatchGroup.leave() return ; }
guard let unwrappedResults = results as? [HKQuantitySample] else { print("get heart rate error"); dispatchGroup.leave(); return}
let heartRatesAsDouble = unwrappedResults.map {$0.quantity.doubleValue(for: heartRateUnit)}
guard let max = heartRatesAsDouble.max() else { dispatchGroup.leave();  return }
let maxAsCustomHistoricalSample = CustomHistoricalSample(value: max, date: workout.startDate)
heartRateMaxArrayAsCustomHistoricalSample.append(maxAsCustomHistoricalSample)
let average = heartRatesAsDouble.average
let averageAsCustomHistoricalSample = CustomHistoricalSample(value: average, date: workout.startDate)
dispatchGroup.leave()
heartRateAvgArrayAsCustomHistoricalSample.append(averageAsCustomHistoricalSample)