Problem mit WMI und wchar

Folgendes klappt:

#define _WIN32_DCOM
#include <iostream>
using namespace std;
#include <comdef.h>
#include <Wbemidl.h>

# pragma comment(lib, "wbemuuid.lib")

int main(int argc, char *argv[])
{
    IWbemLocator            *pLocator       = NULL;
    IWbemServices           *pServices      = NULL;
    IEnumWbemClassObject    *pEnumerator    = NULL;
    IWbemClassObject        *pClsObj        = NULL;
    unsigned long           ulReturn        = 0L;

    SetDebugPrivilege();

    if(FAILED(CoInitializeEx(0, COINIT_MULTITHREADED)))
    {
        cout << "Fehler #100" << endl;
        return EXIT_FAILURE;
    }

    if(FAILED(CoInitializeSecurity(NULL, -1, NULL, NULL, RPC_C_AUTHN_LEVEL_DEFAULT, RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE, NULL)))
    {
        cout << "Fehler #101" << endl;
        return EXIT_FAILURE;
    }

    if(FAILED(CoCreateInstance(CLSID_WbemLocator, 0, CLSCTX_INPROC_SERVER, IID_IWbemLocator, (LPVOID *) &pLocator)))
    {
        cout << "Fehler #102" << endl;
        CoUninitialize();
        return EXIT_FAILURE;
    }

    if(FAILED(pLocator->ConnectServer(_bstr_t(L"ROOT\\CIMV2"), NULL, NULL, 0, NULL, 0, 0, &pServices)))
    {
        cout << "Fehler #103" << endl;
        pLocator->Release();
        CoUninitialize();
        return EXIT_FAILURE;
    }

    if(FAILED(CoSetProxyBlanket(pServices, RPC_C_AUTHN_WINNT, RPC_C_AUTHZ_NONE, NULL, RPC_C_AUTHN_LEVEL_CALL, RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE)))
    {
        cout << "Fehler #104" << endl;
        pServices->Release();
        pLocator->Release();
        CoUninitialize();
        return EXIT_FAILURE;
    }

    if(FAILED(pServices->ExecQuery(bstr_t("WQL"), bstr_t("SELECT * FROM Win32_Process"), WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY, NULL, &pEnumerator)))
    {
        cout << "Fehler #105" << endl;
        pServices->Release();
        pLocator->Release();
        CoUninitialize();
        return EXIT_FAILURE;
    }

    while(pEnumerator)
    {
        pEnumerator->Next(WBEM_INFINITE, 1, &pClsObj, &ulReturn); 

        if(ulReturn == NULL)
            break;

        VARIANT vtProp;

        pClsObj->Get(L"Name", 0, &vtProp, 0, 0);
        wcout << vtProp.bstrVal << endl;

        VariantClear(&vtProp);
        pClsObj->Release();
    }

    pEnumerator->Release();
    pServices->Release();
    pLocator->Release();
    CoUninitialize();

    cin.get();
    return EXIT_SUCCESS;
}

Ändere ich jedoch die Zeile

pClsObj->Get(L"Name", 0, &vtProp, 0, 0);

zu

pClsObj->Get(L"CommandLine", 0, &vtProp, 0, 0);

erhalte ich zur Laufzeit einen "Access violation" Fehler (wcslen.c).
Was mache ich denn falsch?
Vielen Dank!!

Hallo,

Rückgabewert von

pClsObj->Get(L"Name", 0, &vtProp, 0, 0);

prüfen, den Wert von:

vtProp.vt prüfen (kommt da vielleicht VT_EMPTY zurück, wenn keine CommandLine für einen Prozess existiert?), z.B. mit:

if (SUCCEEDED(hr) && (V_VT(&v) == VT_BSTR))

und wenn alles passt, mit SysAllocString/SysFreeString arbeiten:

BSTR prop = SysAllocString(L"CommandLine");
...
SysFreeString(prop);

MfG,

Probe-Nutzer

ich meinte natürlich:

Rückgabewert von

pClsObj->Get(L"CommandLine", 0, &vtProp, 0, 0);

prüfen, ...

MfG,

Probe-Nutzer

DANKE! Das hat prima geklappt!