怎么侦测USB端口上有设备插拔？

WM_DEVICECHANGLE消息，nEventType为DBT_DEVICEARRIVAL且dwData  = 7时就是U盘连接事件（没弄错的话）

我想RegisterDeviceNotification中参数DEV_BROADCAST_DEVICEINTERFACE结构体的GUID dbcc_classguid;为设备的GUID，填什么参数啊？

 

typedef void (__stdcall *FUNC_TYPE_HIDGUID) ( OUT LPGUID HidGuid ); FUNC_TYPE_HIDGUID _HidD_GetHidGuid = NULL; // USB version GUID static GUID GUID_CLASS_ITOKEN2 = {0x171638f7, 0x1ead, 0x4873, {0xba, 0x98, 0xc9, 0x66, 0xab, 0xcf, 0x1, 0x42}}; static GUID GUID_CLASS_ITOKEN2_HID; BOOL bRegisted = FALSE; typedef PVOID HDEVNOTIFY; HDEVNOTIFY hDevNotify1 = NULL; HDEVNOTIFY hDevNotify2 = NULL; void CSample_13Dlg::OnRegister() { // TODO: Add your control notification handler code here HWND hWnd; //HDEVNOTIFY hDevNotify = NULL; DEV_BROADCAST_DEVICEINTERFACE dbf; BOOL bRes; if (_HidD_GetHidGuid == NULL) { HINSTANCE hMod = LoadLibrary("hid.dll"); _HidD_GetHidGuid = (FUNC_TYPE_HIDGUID)GetProcAddress(hMod, "HidD_GetHidGuid"); ASSERT(_HidD_GetHidGuid != NULL); // Get HID device GUID _HidD_GetHidGuid(&GUID_CLASS_ITOKEN2_HID); FreeLibrary(hMod); } if (!bRegisted) // if not registered { hWnd = this->m_hWnd; // Register ITOKEN2 device notification memset(&dbf, 0x00, sizeof(dbf)); dbf.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE); dbf.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE; dbf.dbcc_classguid = GUID_CLASS_ITOKEN2; hDevNotify2 = RegisterDeviceNotification( hWnd, &dbf, DEVICE_NOTIFY_WINDOW_HANDLE ); ASSERT(hDevNotify2 != NULL); // Register ITOKEN2 HID device notification memset(&dbf, 0x00, sizeof(dbf)); dbf.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE); dbf.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE; dbf.dbcc_classguid = GUID_CLASS_ITOKEN2_HID; hDevNotify1 = RegisterDeviceNotification( hWnd, &dbf, DEVICE_NOTIFY_WINDOW_HANDLE ); ASSERT(hDevNotify1 != NULL); GetDlgItem(IDC_REGISTER)->SetWindowText("Unregister"); bRegisted = TRUE; } else { if (hDevNotify1) // Unregister ITOKEN2 device notification { bRes = UnregisterDeviceNotification(hDevNotify1); ASSERT(bRes); } if (hDevNotify2) // Unregister ITOKEN2 HID device notification { bRes = UnregisterDeviceNotification(hDevNotify2); ASSERT(bRes); } GetDlgItem(IDC_REGISTER)->SetWindowText("register"); bRegisted = FALSE; } }