BluetoothLEAdvertisementWatcher Windows 10无法正确扫描信标

Question

我想定期扫描信标，例如每两秒钟扫描一次。 我试图设置SignalStrengthFilter频率的SamplingInterval，但它不起作用。

所以，我尝试使用Timer自己实现这种行为。我实现了一个例程，收集信标信息两秒钟，然后返回在此期间看到的信标列表。但它无法正常工作。

我使用每隔0.5秒传输一次的信标，两秒钟后扫描器没有看到正确数量的信标。每次看到的信标数量都是可变的。

我认为问题是Windows 10的扫描间隔和扫描窗口。 有没有办法调整它们？

这是主要代码：

public void startDecoding()
{
        watcher.Received += OnAdvertisementReceived;
        watcher.Stopped += OnAdvertisementWatcherStopped;          
        watcher.Start();

        t = ThreadPoolTimer.CreatePeriodicTimer((t) =>
               {

                   timerCallback();
               }, TimeSpan.FromSeconds(2));  //every two seconds for example

 }

private  void timerCallback()
{         
     List<Beacon> tmp;

     lock(_sync)
     {                    
         tmp = new List<iBeaconData>(beacons);
         beacons.Clear();
     }

     bc.onBeaconDetected(tmp);

 } 


private async void OnAdvertisementReceived(BluetoothLEAdvertisementWatcher watcher, BluetoothLEAdvertisementReceivedEventArgs eventArgs)
{

        // The timestamp of the event
        DateTimeOffset timestamp = eventArgs.Timestamp;

        // The type of advertisement
        BluetoothLEAdvertisementType advertisementType = eventArgs.AdvertisementType;

        // The received signal strength indicator (RSSI)
        Int16 rssi = eventArgs.RawSignalStrengthInDBm;

        // The local name of the advertising device contained within the payload, if any
        string localName = eventArgs.Advertisement.LocalName;

        // Get iBeacon specific data
        var beaconData = eventArgs.Advertisement.iBeaconParseAdvertisement(eventArgs.RawSignalStrengthInDBm);


        if (beaconData == null)
            return;

        lock(_sync)
        {
            var existing = beacons.Where(b => b.UUID.ToString() == beaconData.UUID.ToString() && b.Major == beaconData.Major && b.Minor == beaconData.Minor).FirstOrDefault();


            if (existing != null)
            {
                 var idx = beacons.IndexOf(existing);
                 beacons.RemoveAt(idx);
            }

            beacons.AddSorted(beaconData);

        }

    }