Swift 2信標掃描在后台

Question

我正在嘗試在我的應用程序中運行信標背景檢測。 我為此創建了一個專用類，並在ViewController中啟動它：

    override func viewDidLoad() {
      super.viewDidLoad()
      beaconSharedInstance
      ....
    }

這是我班上的代碼：

let beaconSharedInstance = iBeacon();

class iBeacon: NSObject, UIApplicationDelegate, CLLocationManagerDelegate {

var locationManager: CLLocationManager!
var beaconRegion:CLBeaconRegion!

override init(){

    super.init()

    let uuidString = "FDA50693-A4E2-4FB1-AFCF-C6EB07640978"
    let beaconIdentifier = "uby-06B524"
    let beaconUUID:NSUUID = NSUUID(UUIDString: uuidString)!
    beaconRegion = CLBeaconRegion(proximityUUID: beaconUUID, identifier: beaconIdentifier)

    locationManager = CLLocationManager()
    locationManager.delegate = self

    if(CLLocationManager.authorizationStatus() != CLAuthorizationStatus.AuthorizedAlways){
        locationManager.requestAlwaysAuthorization()
    }

    locationManager.allowsBackgroundLocationUpdates = true
    locationManager!.startRangingBeaconsInRegion(beaconRegion)
}


func locationManager(manager: CLLocationManager,
                     didRangeBeacons beacons: [CLBeacon],
                                     inRegion region: CLBeaconRegion)  {
    print("didRangeBeacons");

    if(beacons.count > 0) {

        print("Discovered beacon \(beacons[0].rssi) dBM name: \(beacons[0].proximityUUID)")
    }


}

}

該類在前台運行良好，但是一旦我的應用程序變為非活動狀態，就可以在日志文件中看到：

Ending background task

然后CLLocatioManager停止...

我在項目的背景模式下設置了位置更新，並在info.plist文件中設置了NSLocationAlwaysUsageDescription，但是我仍然有相同的行為，當應用程序處於非活動狀態時，線程停止了。

我也試圖像這樣啟動我的線程：

let qualityOfServiceClass = DISPATCH_QUEUE_PRIORITY_DEFAULT
    let backgroundQueue = dispatch_get_global_queue(qualityOfServiceClass, 0)
    dispatch_async(backgroundQueue, {
        print("Running beacon detection in the background queue")
        beaconSharedInstance
    })

但是在那種情況下，CLLocationManager永遠不會啟動...知道嗎？

Answer 1

后台任務需要循環，否則它將退出。 嘗試：

dispatch_async(backgroundQueue, {
    print("Running beacon detection in the background queue")
    beaconSharedInstance
    while(true) {
      NSThread.sleepForTineInterval(1)
      print("running...")
    }
})