用当前的心率更新标签（电子表和手表套件）

Question

单击按钮时，应捕获当前的心率并更新标签。但是，我不明白为什么标签不会随心率值更新。我不知道这里出了什么问题。 就迅捷和手表套件而言，我仍然是一个非常初学者。我希望任何人都能帮助我。

非常感谢您。

在下面您可以看到代码。我还将授权部分添加到AppDelegate.swift文件中。

MERGE

import WatchKit
import Foundation
import HealthKit


class InterfaceController: WKInterfaceController {

    @IBOutlet weak var label: WKInterfaceLabel!
    @IBOutlet weak var button: WKInterfaceButton!

    var isRecording = false

    //For workout session
    let healthStore = HKHealthStore()
    var session: HKWorkoutSession?
    var currentQuery: HKQuery?

    override func awake(withContext context: Any?) {
        super.awake(withContext: context)

        // Configure interface objects here.
    }

    override func willActivate() {
        // This method is called when watch view controller is about to be visible to user
        super.willActivate()
        //Check HealthStore
        guard HKHealthStore.isHealthDataAvailable() == true else {
            print("Health Data Not Avaliable")
            return
        }
    }

    override func didDeactivate() {
        // This method is called when watch view controller is no longer visible
        super.didDeactivate()
    }

    @IBAction func btnPressed() {
        if(!isRecording){
            let stopTitle = NSMutableAttributedString(string: "Stop Recording")
            stopTitle.setAttributes([NSAttributedString.Key.foregroundColor: UIColor.red], range: NSMakeRange(0, stopTitle.length))
            button.setAttributedTitle(stopTitle)
            isRecording = true
            startWorkout() //Start workout session/healthkit streaming
        }else{
            let exitTitle = NSMutableAttributedString(string: "Start Recording")
            exitTitle.setAttributes([NSAttributedString.Key.foregroundColor: UIColor.green], range: NSMakeRange(0, exitTitle.length))
            button.setAttributedTitle(exitTitle)
            isRecording = false
            healthStore.end(session!)
            label.setText("Heart Rate")

        }
    }
}

extension InterfaceController: HKWorkoutSessionDelegate{
    func workoutSession(_ workoutSession: HKWorkoutSession, didChangeTo toState: HKWorkoutSessionState, from fromState: HKWorkoutSessionState, date: Date) {
        switch toState {
        case .running:
            print(date)
            if let query = heartRateQuery(date){
                self.currentQuery = query
                healthStore.execute(query)
            }
        //Execute Query
        case .ended:
            //Stop Query
            healthStore.stop(self.currentQuery!)
            session = nil
        default:
            print("Unexpected state: \(toState)")
        }
    }

    func workoutSession(_ workoutSession: HKWorkoutSession, didFailWithError error: Error) {
        //Do Nothing
    }

    func startWorkout(){
        // If a workout has already been started, do nothing.
        if (session != nil) {
            return
        }
        // Configure the workout session.
        let workoutConfiguration = HKWorkoutConfiguration()
        workoutConfiguration.activityType = .running
        workoutConfiguration.locationType = .outdoor

        do {
            session = try HKWorkoutSession(configuration: workoutConfiguration)
            session?.delegate = self
        } catch {
            fatalError("Unable to create workout session")
        }

        healthStore.start(self.session!)
        print("Start Workout Session")
    }

    func heartRateQuery(_ startDate: Date) -> HKQuery? {
        let quantityType = HKObjectType.quantityType(forIdentifier: HKQuantityTypeIdentifier.heartRate)
        let datePredicate = HKQuery.predicateForSamples(withStart: startDate, end: nil, options: .strictEndDate)
        let predicate = NSCompoundPredicate(andPredicateWithSubpredicates:[datePredicate])

        let heartRateQuery = HKAnchoredObjectQuery(type: quantityType!, predicate: predicate, anchor: nil, limit: Int(HKObjectQueryNoLimit)) { (query, sampleObjects, deletedObjects, newAnchor, error) -> Void in
            //Do nothing
        }

        heartRateQuery.updateHandler = {(query, samples, deleteObjects, newAnchor, error) -> Void in
            guard let samples = samples as? [HKQuantitySample] else {return}
            DispatchQueue.main.async {
                guard let sample = samples.first else { return }
                let value = sample.quantity.doubleValue(for: HKUnit(from: "count/min"))
                print("This line is executed!")
                self.label.setText(String(UInt16(value))) //Update label
            }

        }

        return heartRateQuery
    }

}