// Sets the dialog box iconsinline 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 dialogHWND     g_hDlg;// Mutex, boundary and namespace used to detect previous running instanceHANDLE   g_hSingleton = NULL;HANDLE   g_hBoundary = NULL;HANDLE   g_hNamespace = NULL;// Keep track whether or not the namespace was created or open for clean-upBOOL     g_bNamespaceOpened = FALSE;// Names of boundary and private namespacePCTSTR   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"));    }}