[Solved]ActiveQt - Problem with querySubObject

chris17

Hi,

I am using a OPC Automation library for accessing data from a OPC Server.

Here is the code so far:
@ QAxObject *server=new QAxObject("Matrikon.OPC.Automation.1");
if(server && !server->isNull())
{
//Matrikon simulation opc server
QString uuidServer="{F8582CF2-88FB-11D0-B850-00C0F0104305}";
server->dynamicCall("Connect(QString)",uuidServer);

    qDebug()<<server->dynamicCall("VendorInfo()").toString();

    QAxObject *groups = server->querySubObject("OPCGroups()");

    if(groups && !groups->isNull())
    {
        qDebug()<<groups->dynamicCall("Count()");
        qDebug()<<groups->dynamicCall("VendorInfo()");
    }

}@

The problem is, that the groups object seems to be pointing to the server object.
To test this I called the Count()-method of the OPCGroups class and the VendorInfo()-method of the OPCServer class on the groups object.
Both calls to VendorInfo() succeeded, whether I called it on the server object or on the groups object.
But calling count() on the groups object gave me the following error:
@QAxBase::dynamicCallHelper: Count(): No such property in [unknown]
Candidates are:
ClientName
CurrentTime
control@

I already made a test application in .Net without problems, so I think the typelibrary is working correctly.

What could be the problem here?
Might this be a bug in the querySubObject function?

Thanks,
Christian

chris17

I worked around this problem by using queryInterface instead of dynamicCalls.