It has been stated that an app running a HKWorkoutSession will have special privileges over other watchOS 2 apps, so when a user looks at their Apple Watch, it will go to the view showing running a workout rather than the watch face.
Currently, on both my device and simulator, this is not the case. If I start a HKWorkoutSession and then leave for 5 minutes and then interact with either the Apple Watch, or the Watch Simulator, it presents the watch face.
If I then open my app, it appears to have been frozen, rather than terminated (which is what I imagine happens to other apps). As the UI will update when I need receive a response in my query.updateHandler. Also if I set it to provide haptic feedback every time my query.updateHandler receives a new HKQuantitySample it will do so, so the app must be running in the background in some form.
Has anyone else noticed this behaviour, and am I doing anything wrong, or expecting something I shouldn't?
Here is how I start my HKWorkoutSession:
self.workoutSession = HKWorkoutSession(activityType: HKWorkoutActivityType.Other, locationType: HKWorkoutSessionLocationType.Indoor)
self.healthStore.startWorkoutSession(self.workoutSession) {
success, error in
if error != nil {
print("startWorkoutSession \(error)\n")
self.printLabel.setText("startWorkoutSession \(error)")
self.printLabel.setTextColor(UIColor.redColor())
}
We're seeing that too, for the moment we've made sure 'opens last activity' is configured.
When the UI is active we start a dispatch_timer to request and process data in 1 second intervals.
Make sure you do any significant processing using the NSUserProcessInfo method though and pause the dispatch_timers whenever you are no longer active. You'll get crashes otherwise.
来源：https://stackoverflow.com/questions/31224611/hkworkoutsession-isnt-keeping-app-at-front-of-apple-watch