Why Do I Get Unknown Error From Defraganalysis Method Of The Win32_Volume Class?

Question

0.00/5 (No votes)

See more:

the code is the following :

C++

BSTR MethodName = SysAllocString(L"DefragAnalysis");
BSTR ClassName = SysAllocString(L"Win32_Volume");

IWbemClassObject* pClass = NULL; 
hres = pSvc-> GetObject (ClassName, 0, 0, &pClass, 0); 

IEnumWbemClassObject* pEnumerator = NULL; 
hres = pSvc-> ExecQuery ( 
    bstr_t ("WQL"),  
    bstr_t ("SELECT * FROM Win32_Volume"), 
    WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,  
    NULL, 
    &pEnumerator); 

IWbemClassObject *pclsObj; 
ULONG uReturn = 0; 

while (pEnumerator) 
{ 
    HRESULT hr = pEnumerator-> Next (WBEM_INFINITE, 1,  
        &pclsObj, &uReturn); 

    if (0 == uReturn) 
    { 
        break; 
    }
    VARIANT vtProp;

            if(FAILED(pclsObj->Get(L"__Path", 0, &vtProp, NULL, NULL)))  
            {  
             cout << "Object has no __Path!" << endl;  
             pclsObj->Release();  
             continue;  
             }  
            int test =0;
            //Execute Method 
            IWbemClassObject* pOutParams = NULL; 
            VARIANT varReturnValue;
            hres = pSvc-> ExecMethod (vtProp.bstrVal, MethodName, 0,     
                           //vtProp.bstrVal
            NULL, NULL, &pOutParams, NULL); 
            hres = pOutParams->Get(L"ReturnValue", 0, 
                            &***varReturnValue***, 
                            NULL, 0);
            VariantClear(&varReturnValue);

}

but i get a vaule of 11 of ReturnValue witch means Unknown error could someone help,i 've been looking for a solution for days

i dont know if the problem is in the list of Parameters of ExecMethod or anything else?

Posted 19-May-14 9:03am

ala deli

Updated 19-May-14 11:47am

v2

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Rage · Answer 1 · 2014-05-20T00:52:00

Solution 1

VB

hres = pSvc-> ExecMethod (vtProp.bstrVal, MethodName, 0,
                           //vtProp.bstrVal
            NULL, NULL, &pOutParams, NULL);

The first argument should be a ClassName.
Not too familiar with that kind of code, but I believe that the pOutparams should point on a structure to get the return value of the Defrag call.

Posted 20-May-14 0:52am

Rage

Comments

ala deli 20-May-14 7:19am

thanks for your reply but when i put the first argument as ClassName hres gets negative value(witch means an error )

Rage 20-May-14 7:30am

I think you will need to get _both_ problems fixed before getting a proper return value (first the classname, then the spawn of the output parameters)

ala deli 20-May-14 7:39am

<pre lang="c++">
BSTR MethodName = SysAllocString(L"DefragAnalysis");
BSTR ClassName = SysAllocString(L"Win32_Volume");

IWbemClassObject* pClass = NULL;
hres = pSvc-> GetObject (ClassName, 0, 0, &pClass, 0);

IWbemClassObject* pOutParamsDefinition = NULL;
hres = pClass->GetMethod(MethodName, 0, NULL, &pOutParamsDefinition);

IWbemClassObject* pClassInstance = NULL;
hres = pOutParamsDefinition->SpawnInstance(0, &pClassInstance);

IEnumWbemClassObject* pEnumerator = NULL;
hres = pSvc-> ExecQuery (
bstr_t ("WQL"),
bstr_t ("SELECT * FROM Win32_Volume WHERE DriveType = 3 AND DriveLetter IS NOT NULL"),
WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
NULL,
&pEnumerator);

IWbemClassObject *pclsObj;
IWbemClassObject* pDefragAnalysis = NULL;
ULONG uReturn = 0;

while (pEnumerator)
{
HRESULT hr = pEnumerator-> Next (WBEM_INFINITE, 1,
&pclsObj, &uReturn);

if (0 == uReturn)
{
break;
}
VARIANT vtProp;

if(FAILED(pclsObj->Get(L"__Path", 0, &vtProp, NULL, NULL)))
{
cout << "Object has no __Path!" << endl;
pclsObj->Release();
continue;
}
//int test =0;
//Execute Method
//IWbemClassObject* pOutParams = NULL;
VARIANT varReturnValue;
hres = pSvc-> ExecMethod (ClassName, MethodName, 0, //vtProp.bstrVal
NULL, NULL, &pClassInstance, NULL);
hres = pClassInstance->Get(L"DefragAnalysis", 0, &varReturnValue, NULL, 0);
if (!FAILED(hres))
{
if (varReturnValue.vt == VT_UNKNOWN)
{
int test=0;
}
}
VariantClear(&varReturnValue);
hres = pClassInstance->Get(L"ReturnValue", 0, &varReturnValue, NULL, 0);
VariantClear(&varReturnValue);

}
</pre>
i made this but i still have the same eroor