Triggering events works only two times under windows

[AnnikaJoo]

Library version

10.1.0.1

OS & OS version

Windows 10

Describe the bug

Hello all,

I am using your Nuget Package in my application to determine if specific USB-devices are added or removed. On Windows I have the problem that this functionality works only two times and after that the event is not triggered anymore. Is this a known issue or what could be responsible for this?

To Reproduce

public void WatchUsbActions()
    {
        _usbEventWatcher.UsbDeviceRemoved += (_, device) =>
        {
            // Detect, if we know the device
            var type = ReaderType.IdentifyReader(device.DeviceName);

            // locking variable, set to true, after application is fully initialized
            if (_usbEventProcessingEnabled)
            {
                if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
                {
                    // locking variable to prevent multiple events after device removal
                    if (!_notifiedLock)
                    {
                        _notifiedLock = true;

                        Task.Delay(UsbEventDelay).ContinueWith(t => OnReaderChanged?.Invoke(this, false));
                        Task.Delay(500).ContinueWith(t => _notifiedLock = false); //renable event broadcast
                    }
                }
                else
                {
                    if (type == ReaderType.Unknown)
                    {
                        return;
                    }

                    Task.Delay(UsbEventDelay).ContinueWith(t => OnReaderChanged?.Invoke(this, false));
                }
            }
        };
        _usbEventWatcher.UsbDeviceAdded += (_, device) =>
        {
            // Identify device
            var type = ReaderType.IdentifyReader(device.DeviceName);
            if (type == ReaderType.Unknown)
            {
                return;
            }

            if (_usbEventProcessingEnabled)
            {
                Task.Delay(UsbEventDelay).ContinueWith(t => OnReaderChanged?.Invoke(this, true));
            }
        };

Expected behavior

I expect the events UsbDeviceRemoved and UsbDeviceAdded to be triggered on every usb change

[Jinjinov]

Thank you for noticing this. This is not a known issue.

I tried it with a few devices right now, it works ok for most of them - I can add and remove them many times and it always works.

But I found one device that triggers the added event only one time. I will investigate.

[Jinjinov]

I have found out that this sometimes stops working for unknown reason for some devices:

"SELECT * FROM __InstanceCreationEvent WITHIN 2 WHERE TargetInstance ISA 'Win32_USBControllerDevice'"

This always works for all devices, but it is CPU intensive:

"SELECT * FROM __InstanceCreationEvent WITHIN 2 WHERE TargetInstance ISA 'Win32_PnPEntity'"

I will make a new NuGet version and will provide this as an option.

The default option will be Win32_USBControllerDevice which works for most devices - and you will be able to choose Win32_PnPEntity which works for all devices, but is more CPU intensive.

[Jinjinov]

Fixed in https://github.com/Jinjinov/Usb.Events/releases/tag/v10.1.1.0

[AnnikaJoo]

Thanks for your quick fix. With the option it works now :)