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How to pass a structure to WMI:Calling a Provider Method? RRS feed

  • Question

  • To add a TCPIP PRINTER PORT, I followed the procedure mentioned under c++ section here, I am struggling to pass the printer port inputs parameters. Any help would be highly appreciated..

    {

    HRESULT hres;

        // Step 1: --------------------------------------------------
        // Initialize COM. ------------------------------------------

        hres =  CoInitializeEx(0, COINIT_MULTITHREADED);
        if (FAILED(hres))
        {
            cout << "Failed to initialize COM library. Error code = 0x"
                << hex << hres << endl;
            return 1;                  // Program has failed.
        }

        // Step 2: --------------------------------------------------
        // Set general COM security levels --------------------------

        hres =  CoInitializeSecurity(
            NULL,
            -1,                          // COM authentication
            NULL,                        // Authentication services
            NULL,                        // Reserved
            RPC_C_AUTHN_LEVEL_DEFAULT,   // Default authentication
            RPC_C_IMP_LEVEL_IMPERSONATE, // Default Impersonation
            NULL,                        // Authentication info
            EOAC_NONE,                   // Additional capabilities
            NULL                         // Reserved
            );

        if (FAILED(hres))
        {
            cout << "Failed to initialize security. Error code = 0x"
                << hex << hres << endl;
            CoUninitialize();
            return 1;                    // Program has failed.
        }

        // Step 3: ---------------------------------------------------
        // Obtain the initial locator to WMI -------------------------

        IWbemLocator *pLoc = NULL;

        hres = CoCreateInstance(
            CLSID_WbemLocator,
            0,
            CLSCTX_INPROC_SERVER,
            IID_IWbemLocator, (LPVOID *) &pLoc);

        if (FAILED(hres))
        {
            cout << "Failed to create IWbemLocator object."
                << " Err code = 0x"
                << hex << hres << endl;
            CoUninitialize();
            return 1;                 // Program has failed.
        }

        // Step 4: -----------------------------------------------------
        // Connect to WMI through the IWbemLocator::ConnectServer method

        IWbemServices *pSvc = NULL;

        // Connect to the root\cimv2 namespace with
        // the current user and obtain pointer pSvc
        // to make IWbemServices calls.
        hres = pLoc->ConnectServer(
             _bstr_t(L"ROOT\\CIMV2"), // Object path of WMI namespace
             NULL,                    // User name. NULL = current user
             NULL,                    // User password. NULL = current
             0,                       // Locale. NULL indicates current
             NULL,                    // Security flags.
             0,                       // Authority (for example, Kerberos)
             0,                       // Context object
             &pSvc                    // pointer to IWbemServices proxy
             );

        if (FAILED(hres))
        {
            cout << "Could not connect. Error code = 0x"
                 << hex << hres << endl;
            pLoc->Release();
            CoUninitialize();
            return 1;                // Program has failed.
        }

        cout << "Connected to ROOT\\CIMV2 WMI namespace" << endl;

        // Step 5: --------------------------------------------------
        // Set security levels on the proxy -------------------------

        hres = CoSetProxyBlanket(
           pSvc,                        // Indicates the proxy to set
           RPC_C_AUTHN_WINNT,           // RPC_C_AUTHN_xxx
           RPC_C_AUTHZ_NONE,            // RPC_C_AUTHZ_xxx
           NULL,                        // Server principal name
           RPC_C_AUTHN_LEVEL_CALL,      // RPC_C_AUTHN_LEVEL_xxx
           RPC_C_IMP_LEVEL_IMPERSONATE, // RPC_C_IMP_LEVEL_xxx
           NULL,                        // client identity
           EOAC_NONE                    // proxy capabilities
        );

        if (FAILED(hres))
        {
            cout << "Could not set proxy blanket. Error code = 0x"
                << hex << hres << endl;
            pSvc->Release();
            pLoc->Release();
            CoUninitialize();
            return 1;               // Program has failed.
        }

        // Step 6: --------------------------------------------------
         // set up to call the Win32_Process::Create method
        BSTR ClassName = SysAllocString(L"Win32_TCPIPPrinterPort");

        IWbemClassObject* pClass = NULL;
        hres = pSvc->GetObject(ClassName, 0, NULL, &pClass, NULL);
    IWbemClassObject* pClassInstance = NULL;
        hres = pClass->SpawnInstance(0, &pClassInstance);
    // Create the values for the in parameters
        VARIANT varCommand;


    //varCommand.parray=;
    // i want to pass the below data in a format accepted by varCommand.. how to do it.. and how to call Put
    /*PortName
       HostAddress
        PortNumber
    SNMP
    SNMPDeviceIndex
    CommunityName
    QueueName
    DoubleSpool*/


    pClassInstance->Put(L"NULL", 0,&varCommand, 0);

    }

    Wednesday, August 6, 2014 1:18 PM

Answers