I am trying to add BLE functionality into a classic (WinForms?) C# desktop application, and have added references (Windows.winmd and System.Runtime.WindowsRuntime) to allow me to access the new BLE API recently introduced by Microsoft for Windows 10 UWP applications. I need to create a classic desktop application, as I need to use an older driver device wrapper (teVirtualMIDI) and want to create a .exe, not an app package.
I am referencing the aformentioned libraries from the following locations...
C:\Program Files (x86)\Windows Kits\10\UnionMetadata\Facade\Windows.WinMD
C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETCore\v4.5\System.Runtime.WindowsRuntime.dll
C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETCore\v4.5\System.Runtime.WindowsRuntime.UI.Xaml.dll
At this point, I simply want to be able to view connected services and characteristics in the debug output window, as is done in this blog post...
https://blogs.msdn.microsoft.com/cdndevs/2017/04/28/uwp-working-with-bluetooth-devices-part-1/
It seems that I am getting errors because the BLE API needs to perform async operations, but I am honestly at a loss. The code I have written so far is included below. Essentially, I am receiving errors when trying to call the "GetGattServicesAsync()" method, as Visual Studio says that class "BluetoothLEDevice" does not contain such a definition. That method is included in the online documentation though, and I am wondering why I am not able to access it.
I hope I have given sufficient information, and any help in solving this problem will be more than appreciated. Thank you all for all the helpful advice you give!
using System;
using System.Diagnostics;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;
using Windows.Devices.Bluetooth;
using Windows.Devices.Midi;
using Windows.Devices.Bluetooth.Advertisement;
using Windows.Devices.Bluetooth.GenericAttributeProfile;
using Windows.Devices.Enumeration;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.Storage.Streams;
using Windows.UI.Core;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;
namespace BDBMidiClient
{
public class BLEHandlingDiscovery : Page
{
//private ObservableCollection<BluetoothLEAttributeDisplay> ServiceCollection = new ObservableCollection<BluetoothLEAttributeDisplay>();
//private ObservableCollection<BluetoothLEAttributeDisplay> CharacteristicCollection = new ObservableCollection<BluetoothLEAttributeDisplay>();
public ObservableCollection<BluetoothLEDeviceDisplay> KnownDevices = new ObservableCollection<BluetoothLEDeviceDisplay>();
//private List<DeviceInformation> UnknownDevices = new List<DeviceInformation>();
//private DeviceWatcher deviceWatcher;
//private BluetoothLEDevice bluetoothLeDevice = null;
//private GattCharacteristic selectedCharacteristic;
private void StartBLEDeviceWatcher()
{
string[] requestedProperties = { "System.Devices.Aep.DeviceAddress", "System.Devices.Aep.IsConnected" };
DeviceWatcher deviceWatcher =
DeviceInformation.CreateWatcher(
BluetoothLEDevice.GetDeviceSelectorFromPairingState(false),
requestedProperties,
DeviceInformationKind.AssociationEndpoint);
/*
DeviceWatcher deviceWatcher =
DeviceInformation.CreateWatcher(
"System.ItemNameDisplay:~~\"BDB\"",
requestedProperties,
DeviceInformationKind.AssociationEndpoint);*/
deviceWatcher.Added += DeviceWatcher_Added;
deviceWatcher.Updated += DeviceWatcher_Updated;
deviceWatcher.Removed += DeviceWatcher_Removed;
deviceWatcher.Start();
//Debug.WriteLine(requestedProperties);
}
private async void DeviceWatcher_Added(DeviceWatcher sender, DeviceInformation deviceInfo)
{
Guid gattService = new Guid();
var device = await BluetoothLEDevice.FromIdAsync(deviceInfo.Id);
var services=await device.GetGattServicesAsync();
foreach (var service in services.Services)
{
Debug.WriteLine($"Service: {service.Uuid}");
var characteristics = await service.GetCharacteristicsAsync();
foreach (var character in characteristics.Characteristics)
{
Debug.WriteLine($"Characteristic: {character.Uuid}");
}
}
}
private void DeviceWatcher_Updated(DeviceWatcher sender, DeviceInformationUpdate deviceInfoUpdate)
{
}
private void DeviceWatcher_Removed(DeviceWatcher sender, DeviceInformationUpdate deviceInfoUpdate)
{
}
async void ConnectToBLEDevice(DeviceInformation deviceInformation)
{
BluetoothLEDevice bluetoothLeDevice = await BluetoothLEDevice.FromIdAsync("BDB");
}
private BluetoothLEDeviceDisplay FindBluetoothLEDeviceDisplay(string id)
{
foreach (BluetoothLEDeviceDisplay bleDeviceDisplay in KnownDevices)
{
if (bleDeviceDisplay.Id == id)
{
return bleDeviceDisplay;
}
}
return null;
}
}