Windows COM automation Qt and AutoCAD

[hskoglund]

I see, should be good using the dumpcpp tool, so perhaps try something like:

QList<QVariant> v3;
v3.append(1.0);
v3.append(2.0);
v3.append(3.0);

QVariant point = QVariant::fromValue(v3);
myPaperSpaceClass->AddPoint(point);

Or is this what you've tried already?

[nadamus]

This approach is not working neither. Same exception is thrown.
Regards
Adam

[hskoglund]

Ok time to bring out the big guns, i.e. go native and try with the old style SAFEARRAY, say like this:

SAFEARRAYBOUND rgsabound[1];
rgsabound[0].lLbound = 0;
rgsabound[0].cElements = 3;

SAFEARRAY* psa = SafeArrayCreate(VT_R8, 1, rgsabound);

LONG  rgIndex = 0;
double x = 1.0;
double y = 2.0;
double z = 3.0;

SafeArrayPutElement(psa, &rgIndex, &x);
rgIndex++;
SafeArrayPutElement(psa, &rgIndex, &y);
rgIndex++;
SafeArrayPutElement(psa, &rgIndex, &z);

QVariant point = QVariant::fromValue(psa);
myPaperSpaceClass->AddPoint(point);

Note: if the QVariant::fromValue fails to compile, consider brute-forcing by changing the void *_a[] declaration inside that function AddPoint() that dumpcpp generated for you, to:

void *_a[] = {(void*)&qax_result, (void*)&psa};

Also need a way to make psa variable visible in there, perhaps declare it as a global (quick and dirty :-)

[nadamus]

What I did:
I changed my compiler from MinGW to MSVC and prepared tlh and tli files from the same tlb libraries.
Then I used SAFEARRAY* wrapped with variant_t
Now it works, but sill I wonder why it is not working with QList and QVariant. According to documentation it should, as far as I understand it. Maybe I'm missing something? Hard to say.
Anyway. Thanks for your support. I appreciate it :)
Code looks like this:
variant_t AcadCom::SetVariant(SAFEARRAY** wektor, double* koordynaty,unsigned long wymiar)

{

if(wymiar>0)

{

    SAFEARRAYBOUND granice;

    granice.lLbound=0;

    granice.cElements=wymiar;

    *wektor=SafeArrayCreate(VT_R8,1,&granice);

    double HUGEP* pdFreq;

    SafeArrayAccessData(*wektor,(void HUGEP* FAR*)&pdFreq);

    for(DWORD i=0;i<wymiar;i++)

    {

        *pdFreq++=koordynaty[i]*skala;

    }

    SafeArrayUnaccessData(*wektor);

    variant_t vKoordynaty;

    vKoordynaty.vt=VT_ARRAY|VT_R8;

    vKoordynaty.parray=*wektor;

    return vKoordynaty;

  }

else

{

    return 0;

}

}

bool AcadCom::SetPunkt(double *koordynaty, QString identyfikator)

{

bool sukces=false;

SAFEARRAY *wektor;

IAcadPointPtr pktPtr;

IAcadTextPtr idText;

if(czyPolaczony)

{



   variant_t vKoordynaty=SetVariant(&wektor,koordynaty);



   pktPtr=autoCadAppPtr->ActiveDocument->ModelSpace->AddPoint(vKoordynaty);

    if(pktPtr->GetApplication())

    {

       idText=autoCadAppPtr->ActiveDocument->ModelSpace->AddText(identyfikator.toStdString().c_str(),vKoordynaty,0.005*skala);

        if(idText->GetApplication())

            sukces=true;

        DopasujWidok();

    }

    SafeArrayUnlock(wektor);

    SafeArrayDestroy(wektor);

    vKoordynaty.Clear();

    wektor=NULL;

}

return sukces;

Regards
Adam

[hskoglund]

@nadamus said in Windows COM automation Qt and AutoCAD:
..
Now it works, but sill I wonder why it is not working with QList and QVariant.

I think the culprit is this line:

*wektor=SafeArrayCreate(VT_R8,1,&granice);

had it instead been *wektor=SafeArrayCreate(VT_VARIANT,1,&granice); then a QList<QVariant> should've worked.

Qt's COM support is kind of stuck between a rock (everything is a VARIANT, the Visual Basic COM flavor, functions are called 100% through the IDispatch interface) and a hard place (you can pass native data types like int, doubles etc through COM, the C/C++ COM flavor, functions are called through specialized interfaces based on IUnknown). I remember doing a lot COM coding around the turn of the century, it was really hot then. Nowadays not so much :-)

[china-Qter]

This is the modified part,

variant_t Form::SetVariant(SAFEARRAY **wektor, double *koordynaty, unsigned long wymiar)
{
if(wymiar>0)
{
SAFEARRAYBOUND granice;
granice.lLbound=0;
granice.cElements=wymiar;
*wektor=SafeArrayCreate(VT_R8,1,&granice);

    double HUGEP* pdFreq;
    SafeArrayAccessData(*wektor,(void HUGEP* FAR*)&pdFreq);
    for(DWORD i=0;i<wymiar;i++)
    {
        *pdFreq++=koordynaty[i]*skala;
    }
    SafeArrayUnaccessData(*wektor);
    variant_t vKoordynaty;
    vKoordynaty.vt=VT_ARRAY|VT_R8;
    vKoordynaty.parray=*wektor;
    return vKoordynaty;
}
else
{
    return 0;
}

}

inline AutoCAD::IAcadPoint* IAcadModelSpace::AddPoint(const variant_t & Point)
{
AutoCAD::IAcadPoint* qax_result = 0;
qRegisterMetaTypeAutoCAD::IAcadPoint*("IAcadPoint*", &qax_result);
qRegisterMetaTypeAutoCAD::IAcadPoint("IAcadPoint", qax_result);
void _a[] = {(void)&qax_result, (void*)&Point};
qt_metacall(QMetaObject::InvokeMetaMethod, 42, _a);
return qax_result;
}

call:
double ptV[3];
ptV[0] = 1000.0;
ptV[1] = 1000.0;
ptV[2] = 0.0;
SAFEARRAY *wektor;
variant_t vKoordynaty=SetVariant(&wektor,ptV,3);
ModelSpace->AddPoint(vKoordynaty);

But it's still wrong：Error calling IDispatch member AddPoint: Exception thrown by server
Code : -2147024809
Source :
Description:
Help :
Connect to the exception(int,QString,QString,QString) signal to catch this exception

[hskoglund]

Hi, just checking, in 2019 you used 43:

qt_metacall(QMetaObject::InvokeMetaMethod, 43, _a);

but this year you used 42:

qt_metacall(QMetaObject::InvokeMetaMethod, 42, _a);

has AutoCad changed or?

[JinCoder]

This post is deleted!

[SGaist]

@JinCoder hi and welcome to devnet,

Please use English as it is the main forum language. We have a dedicated international sub forum for people to interact in their main language.

[JinCoder]

@SGaist Ok, I saw his user name is "china-Qter", so I used chinese.