ios - watch 操作系统 2.0 测试版 : access heart beat rate

Question

有了 Watch OS 2.0，开发者应该被允许访问心跳传感器.... 我很想尝试一下，并为我的想法构建一个简单的原型(prototype)，但我找不到任何关于此功能的信息或文档。

谁能告诉我如何完成这项任务？任何链接或信息将不胜感激

Answer 1

从技术上讲，Apple 并未允许开发人员访问 watchOS 2.0 中的心率传感器。他们所做的是提供对 HealthKit 中传感器记录的心率数据的直接访问。要做到这一点并近乎实时地获取数据，您需要做两件主要的事情。首先，您需要告诉 watch 您正在开始锻炼(假设您正在运行):

// Create a new workout session
self.workoutSession = HKWorkoutSession(activityType: .Running, locationType: .Indoor)
self.workoutSession!.delegate = self;

// Start the workout session
self.healthStore.startWorkoutSession(self.workoutSession!)

然后，您可以从 HKHealthKit 开始流式查询，以便在 HealthKit 收到更新时为您提供更新:

// This is the type you want updates on. It can be any health kit type, including heart rate.
let distanceType = HKObjectType.quantityTypeForIdentifier(HKQuantityTypeIdentifierDistanceWalkingRunning)

// Match samples with a start date after the workout start
let predicate = HKQuery.predicateForSamplesWithStartDate(workoutStartDate, endDate: nil, options: .None)

let distanceQuery = HKAnchoredObjectQuery(type: distanceType!, predicate: predicate, anchor: 0, limit: 0) { (query, samples, deletedObjects, anchor, error) -> Void in
    // Handle when the query first returns results
    // TODO: do whatever you want with samples (note you are not on the main thread)
}

// This is called each time a new value is entered into HealthKit (samples may be batched together for efficiency)
distanceQuery.updateHandler = { (query, samples, deletedObjects, anchor, error) -> Void in
    // Handle update notifications after the query has initially run
    // TODO: do whatever you want with samples (note you are not on the main thread)
}

// Start the query
self.healthStore.executeQuery(distanceQuery)

视频末尾的演示中对此进行了详细描述 What's New in HealthKit - WWDC 2015