从蓝牙 BLE 设备检索值

Question

在我的 windows 窗体应用程序中，我开始枚举设备列表，如下所示：

    DeviceWatcher deviceWatcher =
                DeviceInformation.CreateWatcher(
                        BluetoothLEDevice.GetDeviceSelectorFromPairingState(false),
                        requestedProperties,
                        DeviceInformationKind.AssociationEndpoint);
        
    // Register event handlers before starting the watcher.
    // Added, Updated and Removed are required to get all nearby devices
    deviceWatcher.Added += DeviceWatcher_Added;

    // EnumerationCompleted and Stopped are optional to implement.
    deviceWatcher.EnumerationCompleted += DeviceWatcher_EnumerationCompleted;
    deviceWatcher.Stopped += DeviceWatcher_Stopped;

    // Start the watcher.
    deviceWatcher.Start();

找到设备后，我将按如下方式检索服务和特征：

    BluetoothLEDevice btdev;
    List<DeviceInformation> lst = new List<DeviceInformation>();
    GattCharacteristic ch;
    private async void DeviceWatcher_Added(DeviceWatcher sender, DeviceInformation args)
    {
        if (args.Name == "Bluno")
        {
            btdev = await BluetoothLEDevice.FromIdAsync(args.Id);
            GattDeviceServicesResult result = await btdev.GetGattServicesAsync();
            Guid customGuid = new Guid("0000dfb0-0000-1000-8000-00805f9b34fb");
            foreach (GattDeviceService service in result.Services)
            {
                if (customGuid == service.Uuid)
                {
                    GattCharacteristicsResult cresult = await service.GetCharacteristicsAsync();
                    ch = cresult.Characteristics.Where(x => x.Uuid == new Guid("0000dfb1-0000-1000-8000-00805f9b34fb")).FirstOrDefault();
                    ch.ValueChanged += Ch_ValueChanged;
                }
            }
        }
    }

问题在于，即使 BLE 设备每秒持续发送多个值，它也不会触发 ValueChanged 事件。 感谢帮助