QT WMI Classes

[ChrisW67]

To summarise for justatiq:

• The C++ compiler needs to be able to find include files that you do not specify a complete path to, e.g Wbemidl.h. You are using MingW, try issuing

  gcc -v -c helloworld.c

  gcc -v -c helloworld.c

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  to see where it will look by default. The GNU C++ compiler uses "-I" options to add to the include search path.
• "#pragma" directives in source files are compiler specific. Any example on the Microsoft site is specific to their compiler but can give you some hints as to which libraries to link.
• The linker needs to be know which libraries must be linked to satisfy calls you have made, e.g. wbemuuid.lib. The GNU ld linker uses option "-l" (lower case L) for this.
• The linker needs to be able to find libraries to satisfy calls you have made. The GNU ld linker uses option "-L" for this. The default search path is built in. In MingW's case it will be limited to stuff inside MingW.
• Spaces in paths need careful quoting.

These problems are generic compile/link problems and not Qt related.

The qmake system can help invoke the compiler correctly once you know the necessary include paths, library search path, and library names:

• You can adjust the INCLUDEPATH in a Qt Pro file help the compiler find include files.
• You can adjust the LIBS in a Qt Pro file help the linker find library files but you need to get the syntax right.

In Assistant, under "QMake Manual", look at the section headed "qmake Reference"

[justatiq]

Qt has to provide me with something I can configure like delphi does... as I mentioned in my previous post that I can easily use WMI after some settings
and I am not blaming Qt but Qt should provide this or tell me how ?

Yes I know it is compiler who looks for the files( I just said for the argument only).
I have used all the paths, absolute paths but the problem is not solved yet.
But I am trying and hopefully it would be solved.

[wysota]

Qt has to provide me with something I can configure like delphi does...

Qt is a library.

If you buy a car, the producer doesn't supply you with a parking lot, mechanic workshop, garage, streets or a camping compartments to hook up to your brand new car. You have to take care of such things yourself.

as I mentioned in my previous post that I can easily use WMI after some settings
and I am not blaming Qt but Qt should provide this or tell me how ?

Any tool you use won't magically determine where respective files are located on your system (and if they are there at all). If you are not up to the task of locating them yourself, maybe you should pay someone to do it for you.

Yes I know it is compiler who looks for the files( I just said for the argument only).

So why involve Qt in this? Leave Qt out for now, first be able to compile any C/C++ application that uses WMI and only then add Qt to the equation.

[ChrisW67]

Qt has to provide me with something I can configure like delphi does...

The bundled compiler you are using "can easily use WMI after some settings", it is just that the settings you crave are not some pretty, no-brainer check box but a few entries in a configuration file. Delphi's configuration is telling it to use the relevant COM object. C++ is not Deplhi; you will have to do a lot of what the Delphi IDE is hiding from you by yourself.

I have used all the paths, absolute paths but the problem is not solved yet. But I am trying and hopefully it would be solved.

Then there is still something wrong in your paths or the way you have tried to use them. You have not posted much about what you have actually tried so potential helpers can only guess.

Have you tried building a basic WMI example without Qt involved i.e. single file and generic gcc/g++ commands? When you succeed at this you will have gained an insight into how to roll WMI into a wider Qt-based project. Then you should use a simple Qt project to combine with WMI, just read something and print it, before moving on to a larger project.

Your 4 Feb 2010 post indicated that you had not quite grasped the LIBS variable in your pro file and you were given guidance that the syntax was wrong. Have you fixed that? Did you look at the suspect path I pointed out? What do the relevant parts of the pro file look like? Have the error messages from your build changed?

There ultimately should be bits something like:

INCLUDEPATH += "Q:\...\...\include"
LIBS += -L"Q:\...\Microsoft SDKs\Windows\...\lib" -lwbemuuid -l... -l...

INCLUDEPATH += "Q:\...\...\include"
LIBS += -L"Q:\...\Microsoft SDKs\Windows\...\lib" -lwbemuuid -l... -l...

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All of these suggestions have already been made, but the specifics are left for you to fill in.

[faldzip]

@justatiq
Did you ever tried Qt Assistant? I guess you did not... It took me aprox 1min 30s to find answer to your question in Assistant. It is rather faster than 1.5month (it is time elapsed from thread start) so take those advices you got here and RTFM!

[MaikoID]

Hi I've this code and it's working fine on Qt 4.6.3 but if I use Qt 4.7 this function returns me nothing. What am I doing wrong ?

std::string DMI::wmiquery(std::string domain, std::string field)
{
    std::string ret;
 
    if (!objWMIService)
    {
        Log::RegistrarEvento("Leitura abortada: WMI não inicializado.");
        return ret;
    }
 
    //Attempt to use some WMI functions...
    QAxObject *returnList = objWMIService->querySubObject("ExecQuery(QString&)",
                                                          QString("select * from %1").arg(domain.c_str()));
 
    QAxObject * result = returnList->querySubObject("ItemIndex(int)", 0);
    result = result->querySubObject("Properties_()");
 
    QAxObject *enum1 = result->querySubObject("_NewEnum");
    IEnumVARIANT* enumInterface; //to get this, include <windows.h>
    QUuid uuid("{00020404-0000-0000-C000-000000000046}");
    enum1->queryInterface(uuid, (void**)&enumInterface);
 
    QString text;
 
    enumInterface->Reset(); //start at the beginning of the list.
    for (int i=0;i<result->property("Count").toInt();i++)
    {
        VARIANT theItem;
        unsigned long count;
        enumInterface->Next(1,&theItem,&count);
        if (!count)
            break;
        QAxObject *bla = new QAxObject((IUnknown *)theItem.punkVal);      
        // The problem is here.. the Property Name or any other property has empty value
        if (field == QString(bla->property("Name").toString().toLatin1().data()).trimmed().toStdString())
        {
            ret = QString(bla->property("Value").toString().toLatin1().data()).trimmed().toStdString();
            break;
        }
    }
 
    return ret;
}

std::string DMI::wmiquery(std::string domain, std::string field)
{
    std::string ret;
    
    if (!objWMIService)
    {
        Log::RegistrarEvento("Leitura abortada: WMI não inicializado.");
        return ret;
    }
    
    //Attempt to use some WMI functions...
    QAxObject *returnList = objWMIService->querySubObject("ExecQuery(QString&)",
                                                          QString("select * from %1").arg(domain.c_str()));
    
    QAxObject * result = returnList->querySubObject("ItemIndex(int)", 0);
    result = result->querySubObject("Properties_()");
    
    QAxObject *enum1 = result->querySubObject("_NewEnum");
    IEnumVARIANT* enumInterface; //to get this, include <windows.h>
    QUuid uuid("{00020404-0000-0000-C000-000000000046}");
    enum1->queryInterface(uuid, (void**)&enumInterface);
    
    QString text;
    
    enumInterface->Reset(); //start at the beginning of the list.
    for (int i=0;i<result->property("Count").toInt();i++)
    {
        VARIANT theItem;
        unsigned long count;
        enumInterface->Next(1,&theItem,&count);
        if (!count)
            break;
        QAxObject *bla = new QAxObject((IUnknown *)theItem.punkVal);      
        // The problem is here.. the Property Name or any other property has empty value
        if (field == QString(bla->property("Name").toString().toLatin1().data()).trimmed().toStdString())
        {
            ret = QString(bla->property("Value").toString().toLatin1().data()).trimmed().toStdString();
            break;
        }
    }
    
    return ret;
}

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thx,

[high_flyer]

What am I doing wrong ?

1. Poting on the wrong thread (just bacuse your problem has to do with WMI doesn't mean any other thread that has to do with it it a proper place for it).
2. Do some research you self, and tell us the resutls for exmple:

I have stepped through the code in the debugger and saw that 'objWMIService' is null.
I then check my code where 'objWMIService' should be initialized, and it is.

OR

I have stepped through the code in the debugger and saw that result->property("Count") retuns 0,
but I have no idea where the property list is filled to check why it is empty...

Or any other stuff you actually tried to solve YOUR problem - before just laying it for us to do for you!

[MaikoID]

1. Poting on the wrong thread (just bacuse your problem has to do with WMI doesn't mean any other thread that has to do with it it a proper place for it).
2. Do some research you self, and tell us the resutls for exmple:

OR

Or any other stuff you actually tried to solve YOUR problem - before just laying it for us to do for you!

I don't think so. This thread is: How to use WMI, I shown what I did to solve it. I just forgot to mention this part:

#ifndef WIN32
#include <QProcess>
#endif
#include <ctype.h>
#include <algorithm>
#include <QMessageBox>
#include <QList>
#include <QByteArray>
#include <QVariant>
#ifdef WIN32
QAxObject *DMI::objIWbemLocator;
QAxObject *DMI::objWMIService;
#endif
 
DMI::DMI(void)
{
}
 
void DMI::Initialize(void)
{
#ifdef WIN32
    CoInitialize(0);
 
    //get the locator object
    objIWbemLocator = new QAxObject("WbemScripting.SWbemLocator");
 
    //get the main WMI Service
    objWMIService = objIWbemLocator->querySubObject("ConnectServer(QString&,QString&)",QString("."),QString("root\\cimv2"));
#endif
}

#ifndef WIN32
#include <QProcess>
#endif
#include <ctype.h>
#include <algorithm>
#include <QMessageBox>
#include <QList>
#include <QByteArray>
#include <QVariant>
#ifdef WIN32
QAxObject *DMI::objIWbemLocator;
QAxObject *DMI::objWMIService;
#endif

DMI::DMI(void)
{
}

void DMI::Initialize(void)
{
#ifdef WIN32
    CoInitialize(0);
    
    //get the locator object
    objIWbemLocator = new QAxObject("WbemScripting.SWbemLocator");
    
    //get the main WMI Service
    objWMIService = objIWbemLocator->querySubObject("ConnectServer(QString&,QString&)",QString("."),QString("root\\cimv2"));
#endif
}

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That it's all what you need to do to communicate by WMI with Windows on Qt.

I don't give more details because this code worked in Qt 4.6.3 and stops to work in Qt 4.7.2 without any apparently error.

I said what I did, on commented code. All worked perfectly but the properties have no Value. I really don't know what I can do or which Qt 4.7.2 change affect the properly behavior of QAxObject.

QAxObject *bla = new QAxObject((IUnknown *)theItem.punkVal);

QAxObject *bla = new QAxObject((IUnknown *)theItem.punkVal);

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bye and sorry.

[wysota]

Make sure this is really caused by a change to 4.7 as it is very unlikely. Maybe something else has also changed in your system apart Qt.

[high_flyer]

I said what I did, on commented code.

Ok, now I see it (would be a good idea to state in the question that there are comments about your findings in the code).
I did react a bit hard since in recent times there a really a lot of people posting with out putting any thought of their own in to their own problems, expecting to be spoon fed - and since I read the forum between while I build, I read fast and often miss details - so I got a bit edgy.
Sorry about that.

Why do you use the following:

i if (field == QString(bla->property("Name").toString().toLatin1().data()).trimmed().toStdString())
        {
            ret = QString(bla->property("Value").toString().toLatin1().data()).trimmed().toStdString();
            break;
        }

i if (field == QString(bla->property("Name").toString().toLatin1().data()).trimmed().toStdString())
        {
            ret = QString(bla->property("Value").toString().toLatin1().data()).trimmed().toStdString();
            break;
        }

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and not

if (field == bla->property("Name").toString().trimmed().toStdString())
{
   ret = bla->property("Value").toString().trimmed().toStdString();
            break;
}

if (field == bla->property("Name").toString().trimmed().toStdString())
{
   ret = bla->property("Value").toString().trimmed().toStdString();
            break;
}

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[MaikoID]

Ok, now I see it (would be a good idea to state in the question that there are comments about your findings in the code).
I did react a bit hard since in recent times there a really a lot of people posting with out putting any thought of their own in to their own problems, expecting to be spoon fed - and since I read the forum between while I build, I read fast and often miss details - so I got a bit edgy.
Sorry about that.

Why do you use the following:

i if (field == QString(bla->property("Name").toString().toLatin1().data()).trimmed().toStdString())
        {
            ret = QString(bla->property("Value").toString().toLatin1().data()).trimmed().toStdString();
            break;
        }

i if (field == QString(bla->property("Name").toString().toLatin1().data()).trimmed().toStdString())
        {
            ret = QString(bla->property("Value").toString().toLatin1().data()).trimmed().toStdString();
            break;
        }

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and not

if (field == bla->property("Name").toString().trimmed().toStdString())
{
   ret = bla->property("Value").toString().trimmed().toStdString();
            break;
}

if (field == bla->property("Name").toString().trimmed().toStdString())
{
   ret = bla->property("Value").toString().trimmed().toStdString();
            break;
}

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Hi.. I've installed the Qt 4.6.2 to continue developing. Today I install the current version of Qt (4.7.0). If I replace my code for yours the problem persist, all bla's properties have null value.

[high_flyer]

If I replace my code for yours the problem persist, all bla's properties have null value.

My code was not supposed to change anything in the functionality, which is exactly the point!
I asked why you used your code the way you did (with (what seems to be) superfluous conversions)