VARIANT question...

[Hylsan]

Hi
Got a little problem with the line below, i cant understand what i should put after the ",".

SendEvent(LPCTSTR bstrNodeName, VARIANT *pvarNodeValue)

The NodeValue should be "1", but
SendEvent("nodename",1)
doesnt work, giving me the following error;

error C2664: 'SendEvent' : cannot convert parameter 2 from 'const int' to 'struct tagVARIANT *'

Thanks in advance!
/Hylsan

 

[Zyrenthian]

you need to do something like

tagVariant tv;
tv = 1;
SendEvent("nodename",&tv)
Matt

 

[Hylsan]

nope...tried that...and im getting this error;

error C2679: binary '=' : no operator defined which takes a right-hand operand of type 'const int' (or there is no acceptable conversion)

/Hylsan

 

[Zyrenthian]

the variant type should have some member variables. You would need to set them specifically if there are not acceptable conversions. Look at the tagVariant struct and see what it has for member vars. Then set the appropriate type. If the variant type has member funcitons, there should be one that will coincide with the value type. Also, there may be other ways of accessing the variant type. I vaguely remember when I used automation in my program there was a funciton that I called that set the variant type for me.

Matt

 

[Hylsan]

Well...i finally solved it...somehow

It should look like this (for those interested)

tagVARIANT NodeValue;
nisse.boolVal=true;
m_eon1.SendEvent("data_in", &NodeValue);

Thanks for your quick response.

/Hylsan

 

[Guest_imported]

I got the same problem with Hylsan, but I don't understand how you solve the problem. what's the meaning of
nisse.boolVal = true;

*Janus*

 

[Hylsan]

oh im sorry....this is how it should be;

tagVARIANT NodeValue;
NodeValue.boolVal=true;
m_eon1.SendEvent("data_in", &NodeValue);

if its a integer you want to transfer it should look like this;

tagVARIANT NodeValue;
NodeValue.intVal=int;

for a float;

tagVARIANT NodeValue;
NodeValue.fltVal=float;

need any more help feel free to reply.

/Hylsan

 

[sieling]

Hello Hylsan,

Need some help on tagVARIANT. The example you used is to set the value for tagVARIANT. How do we go about reading the value from a tagVARIANT?

Thanks,
Sie

 

[Hylsan]

well...i dont know if any of this will help you, tho this is how the function looks like in my testprogram.
I can recommend looking up "COleVariant" in help/msdn. that looks like a much better way than with tagVariant.

void CAxtestDlg::OnOnEventEonx1(LPCTSTR bstrNodeName, VARIANT FAR* pvarNodeValue)
{
	tagVARIANT test=*pvarNodeValue;
	CString intext=test.bstrVal;

	MessageBox(intext);
}

/Hylsan

 

[richsb]

Hyslan,

From the above I was able to solve my own Variant problem when getting data from the MSComm activeX control which throughs out data in the variant form. Hope this helps others.

void CPortComDlg::OnOnCommMSComm()
{
  tagVARIANT test = m_ctlMSCommPort.GetInput();
  CString intext = test.bstrVal;
  CEdit* pGpsOutputBox = (CEdit*)GetDlgItem(IDC_GPS_OUTPUT_BOX);
  pGpsOutputBox->SetWindowText(intext);
}

NB I had to increase the RThreshold of the port to an appropriate level - say 10 . The above then puts the string data into my edit box for viewing.

The only thing that I need to do now is figure out how to grab the strings I want as they come in various lengths and represent different types of info. Well here's to hoping, but I think that it is pub time!

Cheers

Richard

 

[LazyMe]

There's also a _variant_t, which is there to make living with VARIANTs a bit less painfull...


Greetings,
Rick