dynamicCall and QByteArray - strange characters

[franco.amato]

Hi to all,
doing some test with a com object seems that a com routine that I call with dynamicCall returns a QByteArray or a QString.
Looking at examples of call of such routine seems that it returns an array of bytes where every element is a pointer to a string

I did some tests as this:

QByteArray array = obj->dynamicCall("routine(QString)", "value").toByteArray();
Debugging with visual studio and doing some cout ( qDebug() << array.data() ) I can see very strange characters like this "‰*" in both case, using QByteArray and QString.
The routine called with dymanicCall comunicate with a chinese fingerprint reader. Maybe this is the reason I get such strange characters?

Looking at doc and visual basic example the value returned should be an array of bytes -> returned_value[value1,value2,value3, value4..];

and

value1 = value2 = value3 = should points to a string.

How can I get the value of every value without getting these strange characters?
I hope to get help wysota where are you?

Regards

[ChrisW67]

Can you run the dumpcpp utility against the com object you are working with?

cd somewheresafetowrite
dumpcpp c:\windows\system32\comctl32.ocx

cd somewheresafetowrite
dumpcpp c:\windows\system32\comctl32.ocx

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The resulting cpp and h file should allow you to more directly access the COM objects by simply instantiating them in the typical C++ fashion:

ComctlLib::TreeView m_treeView;
...
m_treeView.SetBorderStyle(ComctlLib::ccFixedSingle);

ComctlLib::TreeView m_treeView;
...
m_treeView.SetBorderStyle(ComctlLib::ccFixedSingle);

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The process can be largely automated by:

client.pro

TEMPLATE = app
CONFIG += qaxcontainer
TARGET = client
DEPENDPATH += .
INCLUDEPATH += .
RC_FILE = client.rc
// {6B7E6392-850A-101B-AFC0-4210102A8DA7} is the TypeLib value from the class concerned.
TYPELIBS = $$system( dumpcpp -getfile {6B7E6392-850A-101B-AFC0-4210102A8DA7} )
isEmpty(TYPELIBS) { 
    message("Tree control type library not found!")
    REQUIRES += COMCTL.TreeView
}
else: {# Input
    SOURCES += main.cpp
}

TEMPLATE = app
CONFIG += qaxcontainer
TARGET = client
DEPENDPATH += .
INCLUDEPATH += .
RC_FILE = client.rc
// {6B7E6392-850A-101B-AFC0-4210102A8DA7} is the TypeLib value from the class concerned.
TYPELIBS = $$system( dumpcpp -getfile {6B7E6392-850A-101B-AFC0-4210102A8DA7} )
isEmpty(TYPELIBS) { 
    message("Tree control type library not found!")
    REQUIRES += COMCTL.TreeView
}
else: {# Input
    SOURCES += main.cpp
}

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[franco.amato]

Can you run the dumpcpp utility against the com object you are working with?

cd somewheresafetowrite
dumpcpp c:\windows\system32\comctl32.ocx

cd somewheresafetowrite
dumpcpp c:\windows\system32\comctl32.ocx

To copy to clipboard, switch view to plain text mode 

The resulting cpp and h file should allow you to more directly access the COM objects by simply instantiating them in the typical C++ fashion:

ComctlLib::TreeView m_treeView;
...
m_treeView.SetBorderStyle(ComctlLib::ccFixedSingle);

ComctlLib::TreeView m_treeView;
...
m_treeView.SetBorderStyle(ComctlLib::ccFixedSingle);

To copy to clipboard, switch view to plain text mode 

The process can be largely automated by:

client.pro

TEMPLATE = app
CONFIG += qaxcontainer
TARGET = client
DEPENDPATH += .
INCLUDEPATH += .
RC_FILE = client.rc
// {6B7E6392-850A-101B-AFC0-4210102A8DA7} is the TypeLib value from the class concerned.
TYPELIBS = $$system( dumpcpp -getfile {6B7E6392-850A-101B-AFC0-4210102A8DA7} )
isEmpty(TYPELIBS) { 
    message("Tree control type library not found!")
    REQUIRES += COMCTL.TreeView
}
else: {# Input
    SOURCES += main.cpp
}

TEMPLATE = app
CONFIG += qaxcontainer
TARGET = client
DEPENDPATH += .
INCLUDEPATH += .
RC_FILE = client.rc
// {6B7E6392-850A-101B-AFC0-4210102A8DA7} is the TypeLib value from the class concerned.
TYPELIBS = $$system( dumpcpp -getfile {6B7E6392-850A-101B-AFC0-4210102A8DA7} )
isEmpty(TYPELIBS) { 
    message("Tree control type library not found!")
    REQUIRES += COMCTL.TreeView
}
else: {# Input
    SOURCES += main.cpp
}

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Hi,
I executed the dumpcpp on my dll ( the com object) but it doesn't generated any *.h or *.cpp
What can I do?

[ChrisW67]

Did you write the com object yousrself? Using QAxServer? If so you probably have a file ending .tlb as part of the build process, and you can put this file name directly in TYPELIBS.

[wysota]

wysota where are you?

I'm having a bad evening.

Besides what was already written I could advise you to check the type of variant returned by dynamic call.

QVariant var = obj->dynamicCall(...);
qDebug() << var->typeName();

QVariant var = obj->dynamicCall(...);
qDebug() << var->typeName();

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[franco.amato]

Did you write the com object yousrself? Using QAxServer? If so you probably have a file ending .tlb as part of the build process, and you can put this file name directly in TYPELIBS.

No I didn't write the com object. It com from a finger print sdk I have. I have it in a compiled dll.
I'm not sure now if I have a tlb file as I'm out of office. If I have it what can I do? And if I don't have it?

[franco.amato]

I'm having a bad evening.

Besides what was already written I could advise you to check the type of variant returned by dynamic call.

QVariant var = obj->dynamicCall(...);
qDebug() << var->typeName();

QVariant var = obj->dynamicCall(...);
qDebug() << var->typeName();

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Ok I'll check tomorrow with the typeName,
for now thank you.

Regards

[ChrisW67]

No I didn't write the com object. It com from a finger print sdk I have. I have it in a compiled dll.
I'm not sure now if I have a tlb file as I'm out of office. If I have it what can I do? And if I don't have it?

You can try

TYPELIBS += C:\path\to\your\fingerprint.dll

TYPELIBS += C:\path\to\your\fingerprint.dll

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which seems to work OK for me for at least some COM objects.

[franco.amato]

You can try

TYPELIBS += C:\path\to\your\fingerprint.dll

TYPELIBS += C:\path\to\your\fingerprint.dll

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which seems to work OK for me for at least some COM objects.

If I also have the *.tlb I have to do

TYPELIBS += C:\path\to\your\fingerprint.dll

TYPELIBS += C:\path\to\your\fingerprint.dll

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And

TYPELIBS += C:\path\to\your\fingerprint.tlb?

TYPELIBS += C:\path\to\your\fingerprint.tlb?

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[ChrisW67]

If you have the TLB file then list it otherwise try listing the DLL or OCX file itself. One or the other, not both.

[franco.amato]

I'm having a bad evening.

Besides what was already written I could advise you to check the type of variant returned by dynamic call.

QVariant var = obj->dynamicCall(...);
qDebug() << var->typeName();

QVariant var = obj->dynamicCall(...);
qDebug() << var->typeName();

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Dear Wysota the result of the

qDebug() << var->typeName();

qDebug() << var->typeName();

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is QByteArray but I don't know how to manage the data. It returns strange characters.

I also generated the *.cpp and *.h files with dumpcpp.
This is the prototype of the routine that give problems to me (from the generated .h):

/*
    Method GetUserData
*/
 inline QVariant GetUserData(const QString& CardID);

/*
    Method GetUserData
*/
 inline QVariant GetUserData(const QString& CardID);

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and the member function implementation ( always in the *.h generated )

inline QVariant oTerminal::GetUserData(const QString& CardID)
{
    QVariant qax_result;
    void *_a[] = {(void*)&qax_result, (void*)&CardID};
    qt_metacall(QMetaObject::InvokeMetaMethod, 71, _a);
    return qax_result;
}

inline QVariant oTerminal::GetUserData(const QString& CardID)
{
    QVariant qax_result;
    void *_a[] = {(void*)&qax_result, (void*)&CardID};
    qt_metacall(QMetaObject::InvokeMetaMethod, 71, _a);
    return qax_result;
}

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I attached here a shot of the visual studio to see the returned value. I hope you can help me.

Regards

[franco.amato]

The resulting cpp and h file should allow you to more directly access the COM objects by simply instantiating them in the typical C++ fashion:

ComctlLib::TreeView m_treeView;
...
m_treeView.SetBorderStyle(ComctlLib::ccFixedSingle);

ComctlLib::TreeView m_treeView;
...
m_treeView.SetBorderStyle(ComctlLib::ccFixedSingle);

To copy to clipboard, switch view to plain text mode 

Hi, I don't understand a thing:
I don't have to use the new operator to instantiate the objects?

[wysota]

Let's ask this first - what would you expect the byte array to contain?

[franco.amato]

Let's ask this first - what would you expect the byte array to contain?

Wysota here the very poor doc I have respect to such routine:

Function: GetUserData
Parameter: CardID(string/10)
Description: Get User Data
Return values: ArrayList

So I expect some sort of array list with different fields as the "set" routine accepts these parameters:

Function: SetUserData
Parameters:
CardID(string/10)
OverWrite(0: no overwrite. If ID is already registered, return with result 06.,1: overwrite.)
idxDesignation
idxDepartment
FirstName(string /15)
LastName(string /15)
idxGroup (integer/0~255)
Status(1 : Activate, 0 : Deactivate)
WorkMode(0:finger+pass ,1:finger,2ass,3:finger or pass,4:Only Crad,5:Only from external Reader,6:Matching on Mifare card)
WorkTimeStart()
WorkTimeEnd()
EmployeeID
RegisterMode( Finger =1, Password = 2, Finger and Password = 3, Card=4, Max=4)
CheckExpire
ExpireDateStart
ExpireDateEnd
Password(string/10)
NF(Number of fingerprint data per user Max. 2)
TemplateSize
FingerData (byte,User Fingerprint data total size depends on the number of fingerprints registered per user)

Description: Set User Data
Return values: True: Successfully

I think the Get routine should returns the same parameters I pass in the Set routine.

Best Regards

[wysota]

Maybe you didn't call the routine correctly and it reports some error or something like that?

[franco.amato]

Maybe you didn't call the routine correctly and it reports some error or something like that?

No I have no errors, and also visual studio says the QByteArray has a size of 441 elements.
I'm thinking to do a com wrapper in c# and call the com routine from it to see the result but from my Qt code how can I get the parameters?

[wysota]

No I have no errors, and also visual studio says the QByteArray has a size of 441 elements.

So maybe everything is there? Try casting the contents of the array to the structure you should be getting and reading the data.

[franco.amato]

So maybe everything is there? Try casting the contents of the array to the structure you should be getting and reading the data.

I don't have such structure. How can I do it?

[wysota]

I meant the ArrayList (or its C++ equivalent) or whatever the return type of the call should be.

[franco.amato]

I meant the ArrayList (or its C++ equivalent) or whatever the return type of the call should be.

Do you mean something like this?
QList<QString> list = static_cast<QList<QString>>(ba.data()) ?