HKAnchoredObjectQuery updateHandler 只调用一次

Question

我在 iPhone 应用程序中有 ViewController：

class ViewController: UIViewController {
    private let healthStore = HKHealthStore()
    private let heartRateUnit = HKUnit(fromString: "count/min")
    private var anchor = HKQueryAnchor(fromValue: Int(HKAnchoredObjectQueryNoAnchor))

    override func viewDidLoad() {
        super.viewDidLoad()

        if let query = createHeartRateStreamingQuery(NSDate()) {
            healthStore.executeQuery(query)
        }
    }

     func createHeartRateStreamingQuery(workoutStartDate: NSDate) -> HKQuery? {
        guard let quantityType = HKObjectType.quantityTypeForIdentifier(HKQuantityTypeIdentifierHeartRate) else { return .None }

        let heartRateQuery = HKAnchoredObjectQuery(type: quantityType, predicate: nil, anchor: anchor, limit: Int(HKObjectQueryNoLimit)) { (query, sampleObjects, deletedObjects, newAnchor, error)  in }

        heartRateQuery.updateHandler = {(query, samples, deleteObjects, newAnchor, error) in
            self.updateHeartRate(samples)
        }

        return heartRateQuery
    }

但是 heartRateQuery.updateHandler 在我使用 Workout 应用程序时只调用了一次。

看起来是同样的错误 - https://forums.developer.apple.com/thread/14571 and

Answer 1

您需要为您的样本类型（心率）启用后台传输。查找方法

HKHealthStore.enableBackgroundDeliveryForType()

我在

之前执行这个方法

HKHealthStore.executeQuery().

Answer 2

更新：Swift 5

您可以指定一个 ObjectType 以及您希望它触发的频率。

HKHealthStore.enableBackgroundDelivery(for: HKObjectType, frequency: HKUpdateFrequency.immediate)

HKAnchoredObjectQuery updateHandler 只调用一次

HKAnchoredObjectQuery updateHandler calls only once

swift

healthkit