WinCE下监视设备插拔的参考代码

      在一些项目中，系统需要实时监测U盘或SD卡的插入拔出。当文件系统加载成功后通知特定应用程序，启动自动播放功能。在U盘或其他外部存储设备移除时，也需要立即通知相应的程序，停止访问这些设备，如播放其中的音视频文件，以免程序出错。

      我们可以使用WinCE设备管理器提供的Device Interface Notification来实现这个功能，参考代码如下。

DWORD WINAPI ThreadFun(LPVOID lpParameter)

{

    HANDLE ph[MAXIMUM_WAIT_OBJECTS];

    HANDLE phMsgQueue[MAXIMUM_WAIT_OBJECTS-1];

    HANDLE phDevNotif[MAXIMUM_WAIT_OBJECTS-1];

    MSGQUEUEOPTIONS msgopts;

    GUID guid[] = {BLOCK_DRIVER_GUID, FSD_MOUNT_GUID};

    DWORD dwCount;

    BYTE pDevBuf[sizeof(DEVDETAIL) + MAX_DEVCLASS_NAMELEN * sizeof(TCHAR)] = {0};

    DEVDETAIL *pd = (DEVDETAIL*)pDevBuf;



    ghExitThread = CreateEvent(NULL, FALSE, FALSE, NULL);



    ph[0] = ghExitThread;

    dwCount = sizeof(guid)/sizeof(GUID);

    for (DWORD i = 0; i < dwCount; i++)

    {

        memset(&msgopts, 0, sizeof(msgopts));

        msgopts.dwFlags = 0;

        msgopts.dwSize = sizeof(msgopts);

        msgopts.dwMaxMessages = 0; 

        msgopts.cbMaxMessage = sizeof(pDevBuf);

        msgopts.bReadAccess = TRUE;



        phMsgQueue[i] = CreateMsgQueue(NULL, &msgopts);

        phDevNotif[i] = RequestDeviceNotifications(guid+i, phMsgQueue[i], TRUE);

        

        ph[i+1] = phMsgQueue[i];

    }



    while (1)

    {

        DWORD dwSize;

        DWORD dwFlags;

        DWORD dwWait;

        DWORD dwQueue;

    

        dwWait = WaitForMultipleObjects(dwCount + 1, ph, FALSE, INFINITE);

        if ((dwWait <= WAIT_OBJECT_0) || (dwWait >= (WAIT_OBJECT_0 + dwCount + 1))) 

        {

            break;

        }



        dwQueue = (dwWait - WAIT_OBJECT_0) - 1;

        

        while(ReadMsgQueue(phMsgQueue[dwQueue], pd, sizeof(pDevBuf), &dwSize, 1, &dwFlags)) 

        {

            if (GUID_ISEQUAL(pd->guidDevClass, BLOCK_DRIVER_GUID))

            {

                printf("\r\nDEV:%S %s", pd->szName, pd->fAttached ? "Add!" : "Removed!");

                if (pd->fAttached)

                {

                    Sleep(10);

                    printf("\r\nOpenStore!");

                    HANDLE h = OpenStore(pd->szName);

                    STOREINFO si;

                    memset(&si, 0 , sizeof(si));

                    si.cbSize = sizeof(si);

                    printf("\r\nGetStoreInfo!");

                    GetStoreInfo(h, &si);

                    printf("\r\n%S %x", si.szStoreName, si.dwDeviceType);

                    CloseHandle(h);

                }

            }

            else if(GUID_ISEQUAL(pd->guidDevClass, FSD_MOUNT_GUID))

            {

                printf("\r\nFSD:%S %s", pd->szName, pd->fAttached ? "Add!" : "Removed!");

            }

            Sleep(1);

        }        

    }

    

    for (DWORD i = 0; i < dwCount; i++) 

    {

        StopDeviceNotifications(phDevNotif[i]);

        CloseMsgQueue(phMsgQueue[i]);

    }    

    CloseHandle(ghExitThread);



    return 0;

}