iBeacon Ranging in background - swift

Question

I'm trying to set my application as a way to just start ringing in the background and get a notification when the user hit the shoulder button or home button(not all the time) and I don't want using background mode. So I coded this in swift, it works when my app is working in foreground and background for 10 seconds and ranging won't be restarted when the user illuminates his phone's screen. First I started background task and then in app delegate I was trying to start ranging for the beacon in the immediate range. Can someone help me about this?
#Background Task
class BackgroundTask1 : NSObject {
private let application: UIApplication!
private var identifier = UIBackgroundTaskInvalid
init(application: UIApplication) {
self.application = application
}
class func run(application: UIApplication, handler: (BackgroundTask1) -> ()) {
let backgroundTask = BackgroundTask1(application: application)
backgroundTask.begin()
handler(backgroundTask)
}
func begin() {
print("begin")
self.identifier = application.beginBackgroundTask {
self.end()
}
}
func end() {
if (identifier != UIBackgroundTaskInvalid) {
application.endBackgroundTask(identifier)
}
identifier = UIBackgroundTaskInvalid
}}
#AppDelegate
func init_()
{
let uuidString = "43F2ACD1-5522-4E0D-9E3F-4A828EA12C24"
let beaconRegionIdentifier = "Hello"
let beaconUUID:UUID = UUID(uuidString:uuidString)!
beaconRegion = CLBeaconRegion(proximityUUID: beaconUUID, identifier: beaconRegionIdentifier)
beaconRegion.notifyEntryStateOnDisplay = true
locationManager = CLLocationManager()
if (CLLocationManager.authorizationStatus() != CLAuthorizationStatus.authorizedWhenInUse) {
locationManager!.requestWhenInUseAuthorization()
}
locationManager!.delegate = self
locationManager!.pausesLocationUpdatesAutomatically=false
}
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
init_()
locationManager?.startRangingBeacons(in: beaconRegion)
return true
}
func applicationWillResignActive(_ application: UIApplication) {
// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}
var timer = Timer()
func applicationDidEnterBackground(_ application: UIApplication) {
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
BackgroundTask1.run(application:
application) { (BackgroundTask1_) in
DispatchQueue.global(qos: .default).async
{
DispatchQueue.main.async {
self.init_()
self.locationManager?.startRangingBeacons(in: self.beaconRegion)
}
}
}
}