swift - Healthkit enableBackgroundDeliveryForType不可用，无法每小时计算心率

Question

我试图在创建 HKObserverQuery 后触发 enableBackgroundDeliveryForType ，但我意识到甚至该方法本身也被禁用了。

/*!
 @method        enableBackgroundDeliveryForType:frequency:withCompletion:
 @abstract      This method enables activation of your app when data of the type is recorded at the cadence specified.
 @discussion    When an app has subscribed to a certain data type it will get activated at the cadence that is specified
                with the frequency parameter. The app is still responsible for creating an HKObserverQuery to know which
                data types have been updated and the corresponding fetch queries. Note that certain data types (such as
                HKQuantityTypeIdentifierStepCount) have a minimum frequency of HKUpdateFrequencyHourly. This is enforced
                transparently to the caller.
 */

那么如何触发一个每小时检查一次心率的工作。

 healthStore.enableBackgroundDeliveryForType(sampleType, frequency: .Immediate, withCompletion: {(succeeded: Bool, error: NSError?) in

        if succeeded{
            print("Enabled background delivery of weight changes")
        } else {
            if let theError = error{
                print("Failed to enable background delivery of weight changes. ")
                print("Error = \(theError)")
            }
        }
    })

以下是我为获取示例而运行的查询。

        let sampleType =  HKObjectType.quantityTypeForIdentifier(HKQuantityTypeIdentifierHeartRate)!

        //let quantityType = HKObjectType.quantityTypeForIdentifier(HKQuantityTypeIdentifierHeartRate)



        let query = HKObserverQuery(sampleType: sampleType, predicate: nil) {
            query, completionHandler, error in

            if error != nil {

                // Perform Proper Error Handling Here...
                print("*** An error occured while setting up the stepCount observer. ***")
                abort()
            }else{
                print("sampleType ",sampleType)
            }
            self.heightChangedHandler()
            completionHandler()
        }

func heightChangedHandler(){
    let sortDescriptor = NSSortDescriptor(key: HKSampleSortIdentifierEndDate,
                ascending: true)

            let sampleType =  HKObjectType.quantityTypeForIdentifier(HKQuantityTypeIdentifierHeartRate)!
            let query = HKSampleQuery(sampleType: sampleType, predicate: nil, limit: Int(HKObjectQueryNoLimit), sortDescriptors: [sortDescriptor]) { (query: HKSampleQuery, results: [HKSample]?, error: NSError?) -> Void in

                guard let results = results where results.count > 0 else {
                    print("Could not read the user's weight")
                    print("or no weight data was available")
                    return
                }

                for sample in results as! [HKQuantitySample]{

                    let heartRate = sample.quantity
                    let heartRateDouble = heartRate.doubleValueForUnit(self.countPerMinuteUnit)
                    print("Sample ",sample.quantity ," tyoe ",sample.quantityType," heartRateDouble ",heartRateDouble)

                }

            }

            healthStore.executeQuery(query)
}

Answer 1

无法安排 watchOS 2.0 应用在后台定期启动以查询 HealthKit 数据。 watchOS 2.0 的应用程序通常只能在 watch 屏幕打开时在前台运行。