Hardware change detection

Introduction

In this article I will describe how to detect device changes in your user-mode applications on the Windows operating system, IOW how to detect the situation when new devices are plugged or removed from the PC (i.e. plug-in USB stick, modem device or mobile phone,  mount/unmount the new disk). Basic approach is receiving notification messages from the system.

Hardware change detecting

Windows sends events to top-level windows about arriving and removing a USB device interface.  All we need to do is to add a handler to handle this event. First of all, we should register our windows to receive device notifications by calling RegisterDeviceNotification function.

This function is defined as follows:

HDEVNOTIFY WINAPI RegisterDeviceNotification(
 __in  HANDLE hRecipient,
 __in  LPVOID NotificationFilter,
 __in  DWORD Flags
);

For the NotificationFilter parameter we will use constant DBT_DEVTYP_DEVICEINTERFACE:

GUID guidForModemDevices = {0x2c7089aa, 0x2e0e, 0x11d1, {0xb1, 0x14, 0x00, 0xc0, 0x4f, 0xc2, 0xaa, 0xe4}};
   DEV_BROADCAST_DEVICEINTERFACE notificationFilter;
   ZeroMemory( &notificationFilter, sizeof(notificationFilter) );
   notificationFilter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
   notificationFilter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
   notificationFilter.dbcc_classguid = guid;

Window  creating
 The hRecipient parameter in described above RegisterDeviceNotification function  is a window handle or a service status handle. In our sample we will use window handle.

Read more: Codeproject

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