问在heartRateVariabilitySDNN LiveWorkoutSession at WatchOS获得Get

EN

    func workoutBuilderDidCollectEvent(_ workoutBuilder: HKLiveWorkoutBuilder) {
    //
    }
    
    func workoutBuilder(_ workoutBuilder: HKLiveWorkoutBuilder, didCollectDataOf collectedTypes: Set<HKSampleType>) {
        for type in collectedTypes{
            print(type)
            guard let quantityType = type as? HKQuantityType else {return}
            let statistics = workoutBuilder.statistics(for: quantityType)
          
            updateForStatistics(statistics)
        }
    }
} 

func updateForStatistics(_ statistics: HKStatistics?) {
        guard let statistics = statistics else { return }

        DispatchQueue.main.async {
            switch statistics.quantityType {
            case HKQuantityType.quantityType(forIdentifier: .heartRate):
                let heartRateUnit = HKUnit.count().unitDivided(by: HKUnit.minute())
                self.heartRate = statistics.mostRecentQuantity()?.doubleValue(for: heartRateUnit) ?? 0
                self.averageHeartRate = statistics.averageQuantity()?.doubleValue(for: heartRateUnit) ?? 0
            case HKQuantityType.quantityType(forIdentifier: .activeEnergyBurned):
                let energyUnit = HKUnit.kilocalorie()
                self.activeEnergy = statistics.sumQuantity()?.doubleValue(for: energyUnit) ?? 0
            case HKQuantityType.quantityType(forIdentifier: .distanceWalkingRunning), HKQuantityType.quantityType(forIdentifier: .distanceCycling):
                let meterUnit = HKUnit.meter()
                self.distance = statistics.sumQuantity()?.doubleValue(for: meterUnit) ?? 0
            case HKQuantityType.quantityType(forIdentifier: .heartRateVariabilitySDNN):
                let sdnnUnit = HKUnit.count()
                self.sdnn = statistics.mostRecentQuantity()?.doubleValue(for: sdnnUnit) ?? 0
            default:
                return
            }
        }
    }