WMI（COM），获取简单信息

Question

我对C ++很新，还在学习。 试图接近例子。但仍然。 在最后一步，我的uReturn为空，所以我得不到我想要的信息。 我错了某处或什么？ 感谢您提供的任何帮助！

#include "stdafx.h"
#define _WIN32_DCOM
#include <iostream>
#include <wbemidl.h>
#include <comdef.h>

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

using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
HRESULT hres;
hres = CoInitializeEx(0, COINIT_MULTITHREADED);

if (FAILED(hres))
{
    cout << "Failed to initialize COM library. Error code = 0x"
        << hex << hres << endl;
    return hres;
}

cout << "COM library initialization OK \n";

hres = CoInitializeSecurity
(
    NULL, 
    -1, 
    NULL, 
    NULL, 
    RPC_C_AUTHN_LEVEL_DEFAULT, 
    RPC_C_IMP_LEVEL_IMPERSONATE, 
    NULL, 
    EOAC_NONE, 
    NULL
);                       

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

cout << "COM security initialization OK \n";

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 hres;
}

cout << "IWbemLocator initialization OK \n";

IWbemServices *pSvc = NULL;

hres = pLoc->ConnectServer
(
    _bstr_t(L"ROOT\\DEFAULT"), 
    NULL, 
    NULL, 
    0, 
    NULL,
    0, 
    0, 
    &pSvc
);

if (FAILED(hres))
{
    cout << "Could not connect. Error code = 0x"
        << hex << hres << endl;
    pLoc->Release();
    CoUninitialize();
    return 1;
}
cout << "Connected to WMI \n";

hres = CoSetProxyBlanket
(
    pSvc,
    RPC_C_AUTHN_WINNT,
    RPC_C_AUTHZ_NONE,
    NULL,
    RPC_C_AUTHN_LEVEL_CALL,
    RPC_C_IMP_LEVEL_IMPERSONATE,
    NULL,
    EOAC_NONE
);

if (FAILED(hres))
{
    cout << "Could not set proxy blanket. Error code = 0x"
        << hex << hres << endl;
    pSvc->Release();
    pLoc->Release();
    CoUninitialize();
    return 1;
}
cout << "Security levels on a WMI connection SET \n";

IEnumWbemClassObject* pEnumerator = NULL;
hres = pSvc->ExecQuery
(
    bstr_t("WQL"),
    bstr_t("SELECT * FROM Win32_OperatingSystem"),
    WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
    NULL,
    &pEnumerator
);

if (FAILED(hres))
{
    cout << "Query for operating system name failed."
        << " Error code = 0x"
        << hex << hres << endl;
    pSvc->Release();
    pLoc->Release();
    CoUninitialize();
    return 1;
}

cout << "Query OK! \n";

IWbemClassObject *pclsObj;
ULONG uReturn = 0;

while (pEnumerator)
{
    cout << "Getting Value... \n";
    HRESULT hr = pEnumerator->Next
    (
        WBEM_INFINITE, 
        1,
        &pclsObj, 
        &uReturn
    );

    if (0 == uReturn)
    {
        cout << "uReturn is NULL! Breaking! \n";
        break;
    }

    VARIANT vtProp;

    hr = pclsObj->Get(L"Name", 0, &vtProp, 0, 0);
    cout << " OS Name : " << vtProp.bstrVal << endl;
    VariantClear(&vtProp);

    pclsObj->Release();
}

cout << "Completed! Cleaning up! \n";

pSvc->Release();
pLoc->Release();
pEnumerator->Release();
CoUninitialize();

return 0;
}