在检测Xamarin.iOS

Question

我在Xamarin.iOS中实现了一个信标检测器应用程序，该应用程序使用以下类来检测 iBeacons 。

递归调用方法StartScanning和GetAvailableBeacons()以获取检测到的信标。但是，在很短的时间内，电池耗电量太大。如何在每60秒后定期进行扫描？经过一番研究，我发现我们可以停止测距。有人可以建议我应该在下面的代码中停止范围吗？

下面是执行iBeacons检测的实现逻辑。

    private CLLocationManager _locationManager;

    private CLBeaconRegion _rBeaconRegion;

    private CLBeaconRegion _eBeaconRegion;

    readonly ObservableCollection<DetectedBeacon> _foundBeacons;


    private ObservableCollection<string> _editableBeaconsList;

    private bool _firstInitialization;


    public BeaconDetector()
    {
        _foundBeacons = new ObservableCollection<DetectedBeacon> ();

        Timer(); // see the implementation below

       _firstInitialization = true;
    }


    private void SetupBeaconRanging(string uuid)
    {
        _locationManager = new CLLocationManager();
        _locationManager.AuthorizationChanged += LocationManagerAuthorizationChanged;
        var rUuid = new NSUuid(uuid);
        _rBeaconRegion = new CLBeaconRegion(rUuid, uuid);

        var eUuid = new NSUuid(uuid);
        _eBeaconRegion = new CLBeaconRegion(eUuid, uuid);

        _rBeaconRegion.NotifyEntryStateOnDisplay = true;
        _rBeaconRegion.NotifyOnEntry = true;
        _rBeaconRegion.NotifyOnExit = true;

        _eBeaconRegion.NotifyEntryStateOnDisplay = true;
        _eBeaconRegion.NotifyOnEntry = true;
        _eBeaconRegion.NotifyOnExit = true;

        _locationManager.DidRangeBeacons += HandleDidRangeBeacons;
        _locationManager.RequestAlwaysAuthorization();



    }

    private void LocationManagerAuthorizationChanged(object sender, CLAuthorizationChangedEventArgs e)
    {
        if (e.Status == CLAuthorizationStatus.AuthorizedAlways)
        {
            _locationManager.StartRangingBeacons(_rBeaconRegion);
        }
    }

    private void HandleDidRangeBeacons(object sender, CLRegionBeaconsRangedEventArgs e)
    {
        if (e.Beacons.Length > 0) // beacons length > 0
        {
            foreach (var b in e.Beacons)
            {
                if (_foundBeacons != null && _foundTrackers.Count > 0)
                {

                      _foundBeacons?.Add(new DetectedBeacon
                            (b.ProximityUuid.ToString(), "", b.Major.ToString(), b.Minor.ToString(), string.Concat(b.Major, b.Minor),null));                
            }
        }
    }

    public void Timer()
    {
        Device.StartTimer(TimeSpan.FromSeconds(20),
            () =>
            {
                SetNewRegion(_rBeaconRegion);

                return true;    
            });
    }


    public void DiscardRegion()
    {
        _locationManager.StopRangingBeacons(_eBeaconRegion);
    }

    public void SetNewRegion(CLBeaconRegion region)
    {
        _locationManager.RequestState(region);

        _locationManager.StartMonitoring(region);

        _locationManager.StartRangingBeacons(region);
    }


    public ObservableCollection<DetectedBeacon> GetAvailableBeacons()
    {
        return !_paused ? _foundBeacons : null;
    }


    public void StartScanning(ObservableCollection<string> beaconList)
    {
        CreatePreDefinedList(beaconList);
        _foundBeacons.Clear();
        DetectRegion();
    }    
}