Cannot get today's steps to display into label

Question

I am trying to create a label which displays today's steps from HealthKit. I have got as far as allowing HealthKit to read/write data, but I'm stuck on actually obtaining the data.

Can anyone offer any advice? Here's my code, including the label I want to display the steps:

import Foundation
import UIKit
import HealthKit


class HealthKitPage : UIViewController
{
      let healthStore: HKHealthStore = HKHealthStore()

      override func viewDidLoad()
      {
                var shareTypes = Set<HKSampleType>()

                shareTypes.insert(HKQuantityType.quantityType(forIdentifier: HKQuantityTypeIdentifier.stepCount)!)

                var readTypes = Set<HKObjectType>()
                readTypes.insert(HKQuantityType.quantityType(forIdentifier: HKQuantityTypeIdentifier.stepCount)!)


                healthStore.requestAuthorization(toShare: shareTypes, read: readTypes) { (success, error) -> Void in
                          if success {
                                    print("success")
                          } else {
                                    print("failure")
                          }

                          if let error = error { print(error) }


                }


      }

      @IBOutlet weak var StepCount: UILabel!



 }

Answer 1

You can fetch today's steps using HKStatisticsQuery. You can now in your view controller use getTodaysSteps method and set your label's text property.

Swift 3.1:

    let healthStore = HKHealthStore()

    func getTodaysSteps(completion: @escaping (Double) -> Void) {
        let stepsQuantityType = HKQuantityType.quantityType(forIdentifier: .stepCount)!

        let now = Date()
        let startOfDay = Calendar.current.startOfDay(for: now)
        let predicate = HKQuery.predicateForSamples(withStart: startOfDay, end: now, options: .strictStartDate)

        let query = HKStatisticsQuery(quantityType: stepsQuantityType, quantitySamplePredicate: predicate, options: .cumulativeSum) { (_, result, error) in
            var resultCount = 0.0

            guard let result = result else {
                log.error("Failed to fetch steps = \(error?.localizedDescription ?? "N/A")")
                completion(resultCount)
                return
            }

            if let sum = result.sumQuantity() {
                resultCount = sum.doubleValue(for: HKUnit.count())
            }

            DispatchQueue.main.async {
                completion(resultCount)
            }
        }

        healthStore.execute(query)
    }

You can call this method like this:

override func viewDidLoad() {
    super.viewDidLoad()

    getTodaysStepCount { [weak self] steps in
        self?.StepCount.text = "\(steps)"
    }
}