public async Task <List <BluetoothDeviceProximityDatum> > ReadPeripheralCharacteristicValuesAsync(CancellationToken cancellationToken)
{
List <BluetoothDeviceProximityDatum> bluetoothDeviceProximityData = new List <BluetoothDeviceProximityDatum>();
// copy list of peripherals to read. note that the same device may be reported more than once. read each once.
List <ScanResult> scanResults;
lock (_scanResults)
{
scanResults = _scanResults.GroupBy(scanResult => scanResult.Device.Address).Select(group => group.First()).ToList();
}
_probe.ReadAttemptCount += scanResults.Count;
// read characteristic from each peripheral
foreach (ScanResult scanResult in scanResults)
{
if (cancellationToken.IsCancellationRequested)
{
break;
}
AndroidBluetoothClientGattCallback readCallback = null;
try
{
readCallback = new AndroidBluetoothClientGattCallback(_service, _characteristic);
BluetoothGatt gatt = scanResult.Device.ConnectGatt(global::Android.App.Application.Context, false, readCallback);
BluetoothGattService service = gatt.GetService(_service.Uuid);
string characteristicValue = null;
bool runningSensus = service != null;
if (runningSensus)
{
characteristicValue = await readCallback.ReadCharacteristicValueAsync(cancellationToken);
}
if (_probe.DiscoverAll || runningSensus)
{
long msSinceEpoch = Java.Lang.JavaSystem.CurrentTimeMillis() - SystemClock.ElapsedRealtime() + scanResult.TimestampNanos / 1000000;
DateTimeOffset encounterTimestamp = new DateTimeOffset(1970, 1, 1, 0, 0, 0, new TimeSpan()).AddMilliseconds(msSinceEpoch);
bluetoothDeviceProximityData.Add(new BluetoothDeviceProximityDatum(encounterTimestamp, characteristicValue, scanResult.Device.Address, scanResult.Device.Name, scanResult.Rssi, scanResult.Device.BondState != Bond.None, runningSensus));
_probe.ReadSuccessCount++;
}
}
catch (Exception ex)
{
SensusServiceHelper.Get().Logger.Log("Exception while reading peripheral: " + ex, LoggingLevel.Normal, GetType());
}
finally
{
readCallback?.DisconnectPeripheral();
}
}
return(bluetoothDeviceProximityData);
}
private async Task <List <BluetoothDeviceProximityDatum> > CreateBluetoothData(CancellationToken cancellationToken)
{
List <BluetoothDeviceProximityDatum> bluetoothDeviceProximityData = new List <BluetoothDeviceProximityDatum>();
// copy list of peripherals to read. note that the same device may be reported more than once. read each once.
List <AndroidBluetoothDevice> le = _bluetoothScannerCallback.GetDiscoveredDevices();
List <AndroidBluetoothDevice> classic = _bluetoothBroadcastReceiver.GetDiscoveredDevices();
List <IGrouping <string, AndroidBluetoothDevice> > scanResults = le.Union(classic)
.GroupBy(scanResult => scanResult.Device.Address)
.ToList();
ReadAttemptCount += scanResults.Count;
// read characteristic from each peripheral
foreach (IGrouping <string, AndroidBluetoothDevice> deviceGroup in scanResults)
{
if (cancellationToken.IsCancellationRequested)
{
break;
}
AndroidBluetoothClientGattCallback readCallback = null;
try
{
readCallback = new AndroidBluetoothClientGattCallback(_deviceIdService, _deviceIdCharacteristic);
BluetoothGatt gatt = deviceGroup.First().Device.ConnectGatt(Application.Context, false, readCallback);
string deviceId = await readCallback.ReadCharacteristicValueAsync(cancellationToken);
if (DiscoverAll || deviceId != null)
{
DateTimeOffset timestamp = deviceGroup.Min(x => x.Timestamp);
string address = deviceGroup.Key;
string name = deviceGroup.FirstOrDefault(x => x.Device.Name != null)?.Device.Name;
int rssi = deviceGroup.Min(x => x.Rssi);
bool paired = deviceGroup.Any(x => x.Device.BondState != Bond.None);
bluetoothDeviceProximityData.Add(new BluetoothDeviceProximityDatum(timestamp, deviceId, address, name, rssi, paired, deviceId != null));
ReadSuccessCount++;
}
}
catch (Exception ex)
{
SensusServiceHelper.Get().Logger.Log("Exception while reading peripheral: " + ex, LoggingLevel.Normal, GetType());
}
finally
{
readCallback?.DisconnectPeripheral();
}
}
return(bluetoothDeviceProximityData);
}
