我正在尝试使用heartRateVariabilitySDNN。我通过查询成功获取了 heartRate,我使用以下代码获取heartRateVariabilitySDNN
但不知道它是如何工作的。Apple 也没有关于此查询或示例代码的适当文档。
func createheartRateVariabilitySDNNStreamingQuery(_ workoutStartDate: Date) -> HKQuery? {
let typeHeart = HKQuantityType.quantityType(forIdentifier: .heartRateVariabilitySDNN)
let predicate: NSPredicate? = HKQuery.predicateForSamples(withStart: workoutStartDate, end: nil, options: HKQueryOptions.strictEndDate)
let squery = HKStatisticsQuery(quantityType: typeHeart!, quantitySamplePredicate: predicate, options: .discreteAverage, completionHandler: {(query: HKStatisticsQuery,result: HKStatistics?, error: Error?) -> Void in
DispatchQueue.main.async(execute: {() -> Void in
print("got: \(String(describing: result))")
})
})
return squery
}