管理员与命名空间绑定、只能运行一个事例、MFC改变图标（windows核心编程）

// Sets the dialog box icons

inline void CMFC_CORE_1Dlg::chSETDLGICONS(HWND hWnd, int idi) {

    ::SendMessage(hWnd, WM_SETICON, ICON_BIG,  (LPARAM)

        LoadIcon((HINSTANCE) ::GetWindowLongPtr(hWnd, GWLP_HINSTANCE),

        MAKEINTRESOURCE(idi)));

    ::SendMessage(hWnd, WM_SETICON, ICON_SMALL, (LPARAM)

        LoadIcon((HINSTANCE) ::GetWindowLongPtr(hWnd, GWLP_HINSTANCE),

        MAKEINTRESOURCE(idi)));

}

void CMFC_CORE_1Dlg::OnDestroy()

{

    CDialogEx::OnDestroy();



    // TODO: 在此处添加消息处理程序代码

    // Don't forget to clean up and release kernel resources

    if (g_hSingleton != NULL) {

        CloseHandle(g_hSingleton);

    }



    if (g_hNamespace != NULL) {

        if (g_bNamespaceOpened) {  // Open namespace

            ClosePrivateNamespace(g_hNamespace, 0);

        } else { // Created namespace

            ClosePrivateNamespace(g_hNamespace, PRIVATE_NAMESPACE_FLAG_DESTROY);

        }

    }



    if (g_hBoundary != NULL) {

        DeleteBoundaryDescriptor(g_hBoundary);

    }

}



// Main dialog

HWND     g_hDlg;



// Mutex, boundary and namespace used to detect previous running instance

HANDLE   g_hSingleton = NULL;

HANDLE   g_hBoundary = NULL;

HANDLE   g_hNamespace = NULL;



// Keep track whether or not the namespace was created or open for clean-up

BOOL     g_bNamespaceOpened = FALSE;



// Names of boundary and private namespace

PCTSTR   g_szBoundary = TEXT("3-Boundary");

PCTSTR   g_szNamespace = TEXT("3-Namespace");



void CMFC_CORE_1Dlg::CheckInstances() {

    // Create the boundary descriptor

    g_hBoundary = ::CreateBoundaryDescriptor(g_szBoundary, 0);



    // Create a SID corresponding to the Local Administrator group

    BYTE localAdminSID[SECURITY_MAX_SID_SIZE];

    PSID pLocalAdminSID = &localAdminSID;

    DWORD cbSID = sizeof(localAdminSID);



    if (!::CreateWellKnownSid(

        WinBuiltinAdministratorsSid, NULL, pLocalAdminSID, &cbSID)

        ) {

            // Using Edit

            CString edit_tring;

            edit_tring.Format(TEXT("AddSIDToBoundaryDescriptor failed: %u\r\n"),GetLastError());

            SetDlgItemText(IDC_EDIT1,edit_tring);

            TRACE(TEXT("AddSIDToBoundaryDescriptor failed: %u\r\n"),GetLastError());

            return;

    }



    // Associate the Local Admin SID to the boundary descriptor

    // --> only applications running under an administrator user

    //     will be able to access the kernel objects in the same namespace

    if (!::AddSIDToBoundaryDescriptor(&g_hBoundary, pLocalAdminSID))

    {

        // Using Edit

        CString edit_tring;

        edit_tring.Format(TEXT("AddSIDToBoundaryDescriptor failed: %u\r\n"),GetLastError());

        SetDlgItemText(IDC_EDIT1,edit_tring);

        TRACE(TEXT("AddSIDToBoundaryDescriptor failed: %u\r\n"),GetLastError());

        return;

    }



    // Create the namespace for Local Administrators only

    SECURITY_ATTRIBUTES sa;

    sa.nLength = sizeof(sa);

    sa.bInheritHandle = FALSE;

    if (!::ConvertStringSecurityDescriptorToSecurityDescriptor(

        TEXT("D:(A;;GA;;;BA)"),

        SDDL_REVISION_1, &sa.lpSecurityDescriptor, NULL))

    {

        // Using Edit

        CString edit_tring;

        edit_tring.Format(TEXT("Security Descriptor creation failed: %u\r\n"), GetLastError());

        SetDlgItemText(IDC_EDIT1,edit_tring);

        TRACE(TEXT("Security Descriptor creation failed: %u\r\n"), GetLastError());

        return;

    }



    g_hNamespace =

        ::CreatePrivateNamespace(&sa, g_hBoundary, g_szNamespace);



    // Don't forget to release memory for the security descriptor

    ::LocalFree(sa.lpSecurityDescriptor);



    // Check the private namespace creation result

    DWORD dwLastError = GetLastError();

    if (g_hNamespace == NULL) {

        // Nothing to do if access is denied

        // --> this code must run under a Local Administrator account

        if (dwLastError == ERROR_ACCESS_DENIED) {

            // Using Edit

            CString edit_tring;

            edit_tring.Format(TEXT("Access denied when creating the namespace.\r\n   You must be running as Administrator.\r\n\r\n"));

            SetDlgItemText(IDC_EDIT1,edit_tring);



            TRACE(TEXT("Access denied when creating the namespace.\r\n"));

            TRACE(TEXT("   You must be running as Administrator.\r\n\r\n"));

            return;

        } else {

            if (dwLastError == ERROR_ALREADY_EXISTS) {

                // If another instance has already created the namespace,

                // we need to open it instead.

                // Using Edit

                CString edit_tring;

                edit_tring.Format(TEXT("CreatePrivateNamespace failed: %u\r\n"), dwLastError);

                SetDlgItemText(IDC_EDIT1,edit_tring);

                TRACE(TEXT("CreatePrivateNamespace failed: %u\r\n"), dwLastError);

                g_hNamespace = OpenPrivateNamespace(g_hBoundary, g_szNamespace);

                if (g_hNamespace == NULL) {

                    edit_tring.Format(TEXT("   and OpenPrivateNamespace failed: %u\r\n"));

                    SetDlgItemText(IDC_EDIT1,edit_tring);

                    TRACE(TEXT("   and OpenPrivateNamespace failed: %u\r\n"),

                        dwLastError);

                    return;

                } else {

                    g_bNamespaceOpened = TRUE;

                    edit_tring.Format(TEXT("   but OpenPrivateNamespace succeeded\r\n\r\n"));

                    SetDlgItemText(IDC_EDIT1,edit_tring);

                    TRACE(TEXT("   but OpenPrivateNamespace succeeded\r\n\r\n"));

                }

            } else {

                // Using Edit

                CString edit_tring;

                edit_tring.Format(TEXT("Unexpected error occured: %u\r\n\r\n"));

                SetDlgItemText(IDC_EDIT1,edit_tring);

                TRACE(TEXT("Unexpected error occured: %u\r\n\r\n"),

                    dwLastError);

                return;

            }

        }

    }



    // Try to create the mutex object with a name

    // based on the private namespace

    TCHAR szMutexName[64];

    StringCchPrintf(szMutexName, _countof(szMutexName), TEXT("%s\\%s"),

        g_szNamespace, TEXT("Singleton"));



    g_hSingleton = CreateMutex(NULL, FALSE, szMutexName);

    if (GetLastError() == ERROR_ALREADY_EXISTS) {

        // There is already an instance of this Singleton object

        // Using Edit

        CString edit_tring;

        edit_tring.Format(TEXT("Another instance of Singleton is running:\r\n--> Impossible to access application features.\r\n"));

        SetDlgItemText(IDC_EDIT1,edit_tring);



        TRACE(TEXT("Another instance of Singleton is running:\r\n"));

        TRACE(TEXT("--> Impossible to access application features.\r\n"));

    } else  {

        // First time the Singleton object is created

        // Using Edit

        CString edit_tring;

        edit_tring.Format(TEXT("First instance of Singleton:\r\n--> Access application features now.\r\n"));

        GetDlgItem(IDC_EDIT1)->SetWindowText(edit_tring);



        TRACE(TEXT("First instance of Singleton:\r\n"));

        TRACE(TEXT("--> Access application features now.\r\n"));

    }

}