Using RegisterDeviceNotification in a .NET Application

Question

I saw some examples of how to use RegisterDeviceNotification from the Windows API, but I did not see any .NET examples. I want to write a C # application that will be notified when a new disk appears (in particular, via USB, firewire, etc.). This application must be a Windows service, so I cannot use WM_DEVICECHANGE messages without any hacking with bad practice. I would like to avoid this. Can someone give me a sample of how to use RegisterDeviceNotification in C # or at least give me a good alternative to it?

EDIT: Again, this is a Windows service that does not have a graphical user interface. Thus, a possible duplicate that includes WM notification messages will not work in this situation.

Answer 1

This article may help: Capturing device events in a C # Windows service

Answer 2

This answer provides relevant code examples for detecting USB devices to remove or add:

using System; using System.Runtime.InteropServices; internal static class UsbNotification { public const int DbtDevicearrival = 0x8000; // system detected a new device public const int DbtDeviceremovecomplete = 0x8004; // device is gone public const int WmDevicechange = 0x0219; // device change event private const int DbtDevtypDeviceinterface = 5; private static readonly Guid GuidDevinterfaceUSBDevice = new Guid("A5DCBF10-6530-11D2-901F-00C04FB951ED"); // USB devices private static IntPtr notificationHandle; /// <summary> /// Registers a window to receive notifications when USB devices are plugged or unplugged. /// </summary> /// <param name="windowHandle">Handle to the window receiving notifications.</param> public static void RegisterUsbDeviceNotification(IntPtr windowHandle) { DevBroadcastDeviceinterface dbi = new DevBroadcastDeviceinterface { DeviceType = DbtDevtypDeviceinterface, Reserved = 0, ClassGuid = GuidDevinterfaceUSBDevice, Name = 0 }; dbi.Size = Marshal.SizeOf(dbi); IntPtr buffer = Marshal.AllocHGlobal(dbi.Size); Marshal.StructureToPtr(dbi, buffer, true); notificationHandle = RegisterDeviceNotification(windowHandle, buffer, 0); } /// <summary> /// Unregisters the window for USB device notifications /// </summary> public static void UnregisterUsbDeviceNotification() { UnregisterDeviceNotification(notificationHandle); } [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] private static extern IntPtr RegisterDeviceNotification(IntPtr recipient, IntPtr notificationFilter, int flags); [DllImport("user32.dll")] private static extern bool UnregisterDeviceNotification(IntPtr handle); [StructLayout(LayoutKind.Sequential)] private struct DevBroadcastDeviceinterface { internal int Size; internal int DeviceType; internal int Reserved; internal Guid ClassGuid; internal short Name; } } 

Use from a WPF window:

  protected override void OnSourceInitialized(EventArgs e) { base.OnSourceInitialized(e); // Adds the windows message processing hook and registers USB device add/removal notification. HwndSource source = HwndSource.FromHwnd(new WindowInteropHelper(this).Handle); if (source != null) { windowHandle = source.Handle; source.AddHook(HwndHandler); UsbNotification.RegisterUsbDeviceNotification(windowHandle); } } /// <summary> /// Method that receives window messages. /// </summary> private IntPtr HwndHandler(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam, ref bool handled) { if (msg == UsbNotification.WmDevicechange) { switch ((int)wparam) { case UsbNotification.DbtDeviceremovecomplete: Usb_DeviceRemoved(); // this is where you do your magic break; case UsbNotification.DbtDevicearrival: Usb_DeviceAdded(); // this is where you do your magic break; } } handled = false; return IntPtr.Zero; } 

Usage from Windows Forms:

 public Form1() { InitializeComponent(); UsbNotification.RegisterUsbDeviceNotification(this.Handle); } protected override void WndProc(ref Message m) { base.WndProc(ref m); if (m.Msg == UsbNotification.WmDevicechange) { switch ((int)m.WParam) { case UsbNotification.DbtDeviceremovecomplete: Usb_DeviceRemoved(); // this is where you do your magic break; case UsbNotification.DbtDevicearrival: Usb_DeviceAdded(); // this is where you do your magic break; } } }