WMI C++ get data from object - c++

Question

I implemented 1-5 steps from :
https://msdn.microsoft.com/en-us/library/aa390423(v=vs.85).aspx
Everyting works, but i have problem with getting data from object which i retreive with query.
My code:
// 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 -------------------------
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
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.
}
//OutputDebugString("Connected to ROOT\\CIMV2 WMI namespace");
// 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.
}
code above is the same as msdn example.
Problem is here:
// Get the currently inserted USB devices
IEnumWbemClassObject* pEnumerator = NULL;
hres = pSvc->ExecQuery(
bstr_t("WQL"),
bstr_t("SELECT * FROM Win32_USBControllerDevice"),
WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
NULL,
&pEnumerator);
if (FAILED(hres))
{
//cout << "Query for USB devices at startup failed."
// << " Error code = 0x"
// << hex << hres << endl;
pSvc->Release();
pLoc->Release();
CoUninitialize();
return 1; // Program has failed.
}
// Get the data from the query
IWbemClassObject *pclsObj = NULL;
ULONG uReturn = 0;
ostringstream os;
while (pEnumerator){
HRESULT hr = pEnumerator->Next(WBEM_INFINITE, 1,
&pclsObj, &uReturn);
if(0 == uReturn){
break;
}
VARIANT vtProp;
VariantInit(&vtProp);
// Get the value of the accessstate property
hr = pclsObj->Get(L"Dependent", 0, &vtProp, 0, 0);
if (FAILED(hr)){
pSvc->Release();
pLoc->Release();
CoUninitialize();
return 1; // Program has failed.
}
os.str("");
os.clear();
os << vtProp.bstrVal;
OutputDebugString(os.str().c_str());
AddDevice(os.str());//Add device to devices vector
VariantClear(&vtProp);
pclsObj->Release();
}
Exactly in this place:
hr = pclsObj->Get(L"Dependent", 0, &vtProp, 0, 0);
This link describes table elements:
https://msdn.microsoft.com/en-us/library/aa394505(v=vs.85).aspx
So i got Dependent value. My problem is how to get this Dependent properties:
https://msdn.microsoft.com/en-us/library/aa387884(v=vs.85).aspx
for example : DeviceID
If anyone can help i will be very very grateful!