ios - 尝试使用 HealthKit 获取步数，但它总是返回 0.0

Question

我正在尝试获取半小时前的步骤，并且我正在使用讨论的方法 here .以下是我的代码:

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

    let now = Date()
    let calendar = Calendar.current
    let halfHourAgoDate = calendar.date(byAdding: .minute, value: -30, to: now)

    if let date = halfHourAgoDate {
        let predicate = HKQuery.predicateForSamples(withStart: date, 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 {
                completion(resultCount)
                return
            }

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

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

        healthStore.execute(query)

    } else {
        print("Error MainVC, date is being cast as nil")
    }
}

当我实际尝试获取步骤时，这是我的代码:

 var todaysSteps: Double = 0
 getSteps(completion: { (resultCount) -> Void in
                                todaysSteps = resultCount
                            })
 print(todaysSteps) // always comes out to 0.0

然而，每当我运行这段代码时，代码都会返回 0.0。我已经启用了 HealthKit，并授权了它的步骤，所以我不确定是什么原因。另请注意，这是在我的变量声明中:

let healthStore = HKHealthStore()

Answer 1

对于遇到相同问题的任何人，您需要在完成处理程序中执行代码，因此:

var todaysSteps: Double = 0
getSteps(completion: { (resultCount) -> Void in
                            print(resultCount)
})