public async Task <List <Tuple <string, DateTimeOffset> > > ReadPeripheralCharacteristicValuesAsync(CancellationToken cancellationToken)
{
List <Tuple <string, DateTimeOffset> > characteristicValueTimestamps = new List <Tuple <string, DateTimeOffset> >();
// copy list of peripherals to read. note that the same device may be reported more than once. read each once.
List <Tuple <CBPeripheral, CBCentralManager, DateTimeOffset> > peripheralCentralTimestamps;
lock (_peripheralCentralTimestamps)
{
peripheralCentralTimestamps = _peripheralCentralTimestamps.GroupBy(peripheralCentralTimestamp => peripheralCentralTimestamp.Item1.Identifier).Select(group => group.First()).ToList();
}
_probe.ReadAttemptCount += peripheralCentralTimestamps.Count;
// read characteristic from each peripheral
foreach (Tuple <CBPeripheral, CBCentralManager, DateTimeOffset> peripheralCentralTimestamp in peripheralCentralTimestamps)
{
if (cancellationToken.IsCancellationRequested)
{
break;
}
TaskCompletionSource <string> readCompletionSource = new TaskCompletionSource <string>();
CBPeripheral peripheral = peripheralCentralTimestamp.Item1;
CBCentralManager central = peripheralCentralTimestamp.Item2;
DateTimeOffset timestamp = peripheralCentralTimestamp.Item3;
#region discover services
peripheral.DiscoveredService += (sender, e) =>
{
try
{
if (e.Error == null)
{
SensusServiceHelper.Get().Logger.Log("Discovered services. Discovering characteristics...", LoggingLevel.Normal, GetType());
// discover characteristics for newly discovered services that match the one we're looking for
foreach (CBService service in peripheral.Services)
{
if (service.UUID.Equals(_service.UUID))
{
peripheral.DiscoverCharacteristics(new CBUUID[] { _characteristic.UUID }, service);
}
}
}
else
{
throw new Exception("Error while discovering services: " + e.Error);
}
}
catch (Exception ex)
{
SensusServiceHelper.Get().Logger.Log("Exception while discovering characteristics: " + ex.Message, LoggingLevel.Normal, GetType());
}
};
#endregion
#region discover characteristics
peripheral.DiscoveredCharacteristic += (sender, e) =>
{
try
{
if (e.Error == null)
{
SensusServiceHelper.Get().Logger.Log("Discovered characteristics. Reading value...", LoggingLevel.Normal, GetType());
// read characteristic value for newly discovered characteristics that match the one we're looking for
foreach (CBCharacteristic characteristic in e.Service.Characteristics)
{
if (characteristic.UUID.Equals(_characteristic.UUID))
{
peripheral.ReadValue(characteristic);
}
}
}
else
{
throw new Exception("Error while discovering characteristics: " + e.Error);
}
}
catch (Exception ex)
{
SensusServiceHelper.Get().Logger.Log("Exception while reading characteristic values from peripheral: " + ex.Message, LoggingLevel.Normal, GetType());
}
};
#endregion
#region update characteristic value
peripheral.UpdatedCharacterteristicValue += (sender, e) =>
{
try
{
if (e.Error == null)
{
// characteristic should have a non-null value
if (e.Characteristic.Value == null)
{
throw new Exception("Null updated value for characteristic.");
}
else
{
SensusServiceHelper.Get().Logger.Log("Value read.", LoggingLevel.Normal, GetType());
string characteristicValue = Encoding.UTF8.GetString(e.Characteristic.Value.ToArray());
readCompletionSource.SetResult(characteristicValue);
}
}
else
{
throw new Exception("Error while updating characteristic value: " + e.Error);
}
}
catch (Exception ex)
{
SensusServiceHelper.Get().Logger.Log("Exception while reporting characteristic value: " + ex.Message, LoggingLevel.Normal, GetType());
}
};
#endregion
try
{
SensusServiceHelper.Get().Logger.Log("Connecting to peripheral...", LoggingLevel.Normal, GetType());
central.ConnectPeripheral(peripheral);
string characteristicValue = await BluetoothDeviceProximityProbe.CompleteReadAsync(readCompletionSource, cancellationToken);
if (characteristicValue != null)
{
characteristicValueTimestamps.Add(new Tuple <string, DateTimeOffset>(characteristicValue, timestamp));
_probe.ReadSuccessCount++;
}
}
catch (Exception ex)
{
SensusServiceHelper.Get().Logger.Log("Exception while reading peripheral: " + ex, LoggingLevel.Normal, GetType());
}
finally
{
DisconnectPeripheral(central, peripheral);
}
}
return(characteristicValueTimestamps);
}
public Task <string> ReadCharacteristicValueAsync(CancellationToken cancellationToken)
{
return(BluetoothDeviceProximityProbe.CompleteReadAsync(_readCompletionSource, cancellationToken));
}
