/// <summary>
/// Stop the scan and notify the caller that it has ended
/// </summary>
private void StopScan()
{
Log("Stop BLE scan");
BluetoothLeScannerCompat scanner = BluetoothLeScannerCompat.Scanner;
if (_scanning && scanner != null && _skfScanCallback != null)
{
// Hold onto this scan callback so we can flush it before any following scan
_previousScanCallback = _skfScanCallback;
scanner.StopScan(_skfScanCallback);
_scanTimer?.Stop();
_scanning = false;
// Invoke the caller's callback so they know the scan finished
DiscoveryFinished?.Invoke(this, new EventArgs());
}
// Clear the event handlers
if (_skfScanCallback != null)
{
Log(string.Format("StopScan: {0} callbacks cleared", _skfScanCallback.ClearCallers()));
// _skfScanCallback.Dispose();
_skfScanCallback = null;
}
//_scanTimer?.Dispose();
_scanTimer = null;
}
/// <summary>
/// Scan for a single device using its address
/// </summary>
/// <param name="iDiscoveryFinished">Event handler for caller to be notified when the scan has completed</param>
/// <param name="iDeviceAddress">Device address in the form of a GUID string</param>
/// <param name="iScanSeconds">Number of seconds to scan; set to zero for indefinite</param>
/// <returns></returns>
public bool ScanSingleDevice(EventHandler iDiscoveryFinished, string iDeviceAddress, int iScanSeconds = 0)
{
// Hold the event handler
DiscoveryFinished = iDiscoveryFinished ?? throw new ArgumentNullException("Disovery finished event handler must be specified");
try
{
// Clear list of received devices
FoundDevices.Clear();
// Ensure it has stopped
StopScan();
BluetoothLeScannerCompat scanner = BluetoothLeScannerCompat.Scanner;
ScanSettings settings = new ScanSettings.Builder()
.SetLegacy(false)
.SetScanMode(ScanSettings.ScanModeLowLatency)
.SetUseHardwareBatchingIfSupported(false).Build();
List <ScanFilter> filters = new List <ScanFilter>();
// Add filter to return only the specified device
filters.Add(new ScanFilter.Builder().SetDeviceAddress(iDeviceAddress).Build());
_skfScanCallback = new NordicScanCallBack();
// Add in the event handlers
_skfScanCallback.ScanResult += Receiver_ScanResult;
_skfScanCallback.ScanFailure += Receiver_ScanFailure;
// Scan
scanner.StartScan(filters, settings, _skfScanCallback);
_scanning = true;
if (iScanSeconds != 0)
{
// Use a timer to end the scan
_scanTimer = new Timer(iScanSeconds * 1000);
_scanTimer.Elapsed += _scanTimer_Elapsed;
_scanTimer.AutoReset = false;
_scanTimer.Start();
}
return(true);
}
catch (Exception ex)
{
Log(string.Format("Exception thrown in ScanSingleDevice: {0}", ex.Message));
return(false);
}
}
/// <summary>
/// Initiate a BLE scan
/// </summary>
/// <param name="iDiscoveryFinished">Event handler for caller to be notified when the scan has completed</param>
/// <param name="iScanSeconds">Number of seconds to scan; set to zero for indefinite</param>
/// <param name="iServiceId">Optional service ID (GUID string) to filter scan results; set to null to skip</param>
/// <param name="iManufacturerId">Optional filter on manufacturer ID; set to zero or omit to skip</param>
/// <returns>True if apparently successul</returns>
public bool Scan(EventHandler iDiscoveryFinished, int iScanSeconds, string iServiceId = null, int iManufacturerId = 0)
{
// Hold the event handler
DiscoveryFinished = iDiscoveryFinished ?? throw new ArgumentNullException("Disovery finished event handler must be specified");
// Ensure the adaptor is present
CreateAdaptor();
try
{
// Clear list of received devices
FoundDevices.Clear();
// Ensure it has stopped
StopScan();
BluetoothLeScannerCompat scanner = BluetoothLeScannerCompat.Scanner;
// If there was a previous scan, flush its results before we start another
//if (_previousScanCallback != null)
//{
// scanner.FlushPendingScanResults(_previousScanCallback);
// _previousScanCallback = null;
//}
ScanSettings settings = new ScanSettings.Builder()
.SetLegacy(false)
.SetScanMode(ScanSettings.ScanModeLowLatency)
//.SetReportDelay(1000)
.SetUseHardwareBatchingIfSupported(false).Build();
List <ScanFilter> filters = new List <ScanFilter>();
if (!string.IsNullOrEmpty(iServiceId))
{
ParcelUuid mUuid = ParcelUuid.FromString(iServiceId);
filters.Add(new ScanFilter.Builder().SetServiceUuid(mUuid).Build());
}
if (iManufacturerId != 0)
{
filters.Add(new ScanFilter.Builder().SetManufacturerData(iManufacturerId, new byte[1] {
0
}, new byte[1] {
0
}).Build());
}
_skfScanCallback = new NordicScanCallBack();
// Add in the event handlers
_skfScanCallback.ScanResult += Receiver_ScanResult;
_skfScanCallback.ScanFailure += Receiver_ScanFailure;
// Scan
scanner.StartScan(filters, settings, _skfScanCallback);
_scanning = true;
if (iScanSeconds != 0)
{
// Use a timer to end the scan
_scanTimer = new Timer(iScanSeconds * 1000);
_scanTimer.Elapsed += _scanTimer_Elapsed;
_scanTimer.AutoReset = false;
_scanTimer.Start();
}
return(true);
}
catch (Exception ex)
{
Log(string.Format("Exception thrown in Scan: {0}", ex.Message));
return(false);
}
}
