Re: VBScript and COM Inf. with ByRef - COM Discussion Boards

21-Aug-02 6:57

Hello,

why i can't make any changes to a ByRef passed Com MEthod Variable ?
The variable ha s the same value before and after the Com Method invokation.

Any Ideas ?

Ernest Laurentin21-Aug-02 7:09

21-Aug-02 7:09

The behaviour is clear once we look at the IDL file

HRESULT Run(
            [in] BSTR ProcedureName, 
            [in] SAFEARRAY(VARIANT)* Parameters, 
            [out, retval] VARIANT* pvarResult);

Which means your parameters are passed by value [in] and not by reference [in,out].

VOTD: 27 "Religion that God our Father accepts as pure and faultless is this:
to look after orphans and widows in their distress and to keep oneself from being polluted by the world." - Jam 1:27 (NIV)

Anonymous21-Aug-02 9:31

21-Aug-02 9:31

Hello,

means retval that the scripting host knows, that he can change the variable ?
I've made ...[out] long* _value);

In VBScript i use ... CLng(_variantvar) to make the conversions.
Can i use only Variant Vars in the COM Interface ?

Ernest Laurentin21-Aug-02 9:50

21-Aug-02 9:50

Well '[out,retval]' is used only for return value. '[in]' says that whatever you passed to your script function, you can't change it inside of your script since data are passed by value. Think of it as a C++ function:
int Sum(int num1, int num2) { return num1+ num2; }
changes to num1 and num2 affect local value only and 'return' is like a constant. I hope it is clearer now. Wink | ;)

Anonymous21-Aug-02 22:12

21-Aug-02 22:12

Hello,

thanks, now it works !
BUT, is there no posibility to make this without to use a return variable ?
My VB Programms and C++ Clients are all working perfectly with a ByRef Call.
Must i really change all clients to use the RetVal, only because i want to use COM-Scripting with VBScript ?
In VBScript i can made ByRef Callings without problems.

Like :
Sub DoSubroutine( )
Dim x
x = 10
msgbox x
CallAnotherSub x
msgbox x
End Sub

Sub CallAnotherSub(ByRef var1)
var1 = var1^2
End Sub

Ernest Laurentin22-Aug-02 7:38

22-Aug-02 7:38

Well VB and VBScript are different. VB supports a whole lot more data types than VBScript.

VOTD: 15 "The eyes of the Lord are on the righteous and his ears are attentive to their cry;
16 the face of the Lord is against those who do evil, to cut off the memory of them from the earth. " - Psalm 34:15-16 (1 Peter 3:11-12) (NIV)

Anonymous22-Aug-02 0:46

22-Aug-02 0:46

Hello Ernest,

i ve noticed, that the article "Adding VBScript and JScript support in ..."
is yours. That had inspired me to make my COM-Servers available to scripting.
Now i've made my COM INterfaces scriptable und the next Problem occurs.

I need the Event's from my COM Objects in the VBScript. I have made it with
" Set msport = WScript.CreateObject("MSCOMSRV.Port","msport_") ". This is OK, if i runs it from the shell with WSH. In your Applikation i get the error
" Object needed WScript ". In which enviroment are the Scripts running (in your Application) ?.

My thought was to make the custom-Scripts like Plug-Ins in my C++ Main Applikation.

Koep ( author of the anonymous messages in the thread, but i ve forgot my password and the remind me action failed )

Ernest Laurentin22-Aug-02 6:52

22-Aug-02 6:52

"WScript" is a different 'HOST' engine than the ActiveX version. I am still planning to write an article about it (give me 1-2 week). You can create COM object from your script and catch the event. In VBScript, create your activex (COM object) by calling

VBScript

Set MsCOMSVR = CreateObject("MSCOMSRV.Port")

MsCOMSVR_OnEvent is the name of the event function. MsCOMSVR must be global in VBScript, if you declare it inside of a 'Sub' it will be destroyed when the 'Sub' terminates.

Koep25-Aug-02 22:04

Koep

25-Aug-02 22:04

Are u sure ?

I think, and my tests confirm this, that u can't use events in normal VBScript. When i use "Set msport = WScript.CreateObject("MSCOMSRV.Port","msport_")" then it's possible. Because the WSH can do event action. The "wscript.sleep 10000" is also important for the event listening stuff. How would u do this without the WScript object ? The WScript can't used from the msscript.ocx . So i have no idea to make event-scripting available from C++ Code, because i don't want to create 10th or 100th of individual WScript processes.

Marco

Ernest Laurentin27-Aug-02 5:21

27-Aug-02 5:21

Yep! it is possible, hopefully I will submit a new article this coming weekend that
demonstrate just that. Watch for it Saturday or Sunday! Big Grin | :-D

ÿVOTD: 8 "Love never fails. But where there are prophecies, they will cease;
where there are tongues, they will be stilled; where there is knowledge, it will pass away." - 1 Cor 13:8 (NIV)

Ernest Laurentin27-Aug-02 8:08

27-Aug-02 8:08

I just re-read your comment correctly and you are right about it. MSscript.ocx does not allow you to handle script event from your script but funnyly you can add/connect object with it.

ÿVOTD: 8 "Love never fails. But where there are prophecies, they will cease;
where there are tongues, they will be stilled; where there is knowledge, it will pass away." - 1 Cor 13:8 (NIV)

receiving data

Lily1820-Aug-02 9:57

Lily18

20-Aug-02 9:57

My program is a client (c++) that link to an activex dll created in VB.
I use this function :

hresult = m_connection->LoadData(OLESTR("01"),OLESTR("B20"), 0,0,&ResulVar,OLESTR("thisMachine"),ADO_ODBC , &m_E );

Hresult tells me everything worked fine but ResulVar return empty.
ResulVar is a VARIANT.
m_E is an object that receive error from the server. It tells me that :
ActiveX component can't create object.(usualy, it's when dll are not registred)
With an other program in vb I tested the same function an it worked perfectly, so I know my dll are registered.
If it can provide me with the error message from m_E, Why the VARIANT doesn't receive the data?
Does anyone have a clue?
Thanks

How to put HTML?

User 100963419-Aug-02 8:20

User 1009634

19-Aug-02 8:20

I want to put HTML code to MSHTML.
The code contains "FRAMESET" tag.

I tried,,,

IHTMLDocument3* doc3;
////get pointer
doc3->get_documentElement(&pElement);
pElement->put_outerHTML(L"~~~~")

But I couldn't put HTML code.

I tried next,,

doc2->get_body(&pElement);
pElement->put_innerHTML(L"~~~~")

But I couldn't put HTML code.

How to put HTML code??
Please tell me.
I thought hardly.

CodeProjectSQ19-Aug-02 9:29

CodeProjectSQ

19-Aug-02 9:29

Try this. It works for me. From Steve.

MSHTML::IHTMLElementPtr spEle;
MSHTML::IHTMLDocument2Ptr spDoc2;
CString sHtml;

sHtml = "some HTML text here";

// get spDoc2 from CHtmlView
spDoc2 = m_pBrowserApp->get_Document( (IDispatch**)&spDoc2 );
if ( spDoc2 == NULL )
return;

spEle = spDoc2->Getbody();
if ( spEle == NULL )
return;

spEle->PutinnerHTML( (LPCTSTR)sHtml );

Stephane Rodriguez.19-Aug-02 10:38

Stephane Rodriguez.

19-Aug-02 10:38

Unlikely to work, just because in HTML a tag is not inside a tag.

I would suggest to do instead : doc3->Write("..."); (which is the equivalent of Javascript's document.write("...") ),

And I swallow a small raisin.

S.A.19-Aug-02 16:00

S.A.

19-Aug-02 16:00

I tried,,

BSTR bstr = SysAllocString(L"~~~");

SafeArrayCreateVector(VT_VARIANT, 0, 1);
SafeArrayAccessData(sfArray,(LPVOID*) & param);
param->vt = VT_BSTR;
param->bstrVal = bstr;
SafeArrayUnaccessData(sfArray);
document->write(sfArray);

But 'FRAME page' is blank page.
Of course,The Page exists.
I think document reset.

Please tell me another method.
Is it impossible ?

String Passing in COM component

Stephane Rodriguez.19-Aug-02 18:59

Stephane Rodriguez.

19-Aug-02 18:59

That works fine. In fact, when you do the equivalent of document.write() when the document is finished loading, IE simply creates a new one and put your HTML code in it. So, you should see the frames for your frameset.

Please remember that a frameset by itself is a very special HTML tag that has no meaning inside an HTML ....

If your aim is only to have one or more frames, I would recommend to use the tag instead, and use putinnerhtml,

And I swallow a small raisin.

abhinarulkar18-Aug-02 21:23

abhinarulkar

18-Aug-02 21:23

Hi Everybody,
I want to take a Character string as a input parameter to a COM component created in VC++ using ATL.How do I perform this task.It would be better if the solution is also given for returning a character string as the output parameter of the COM component.

Thanks and Regards,
Abhishek.

Learning is a never ending process of Life.

Jason Henderson19-Aug-02 2:53

Jason Henderson

19-Aug-02 2:53

Use a BSTR.
First pram below is how you pass it in, second is how you make it a return value.

HRESULT MyFunc(BSTR bstrParam, [out, retval]BSTR *bstrRetVal)

Jason Henderson
_{quasi-homepage}
^articles
_{"Like it or not, I'm right!"}

b_p_smith26-Aug-02 13:17

b_p_smith

26-Aug-02 13:17

Just so I'm clear, what the best way to deal with this in a way that's "friendly" to both C++ and VB (I work exclusively in C++ myself)?

I'd envision a C++ calling sequence similar to:

BSTR* pbstrFoo = NULL;<br />
MyFunc(pbstrFoo);<br />
// MyFunc calls ::SysAllocString and fills the BSTR<br />
if(NULL != pbstrFoo)<br />
{<br />
  // use pbstrFoo<br />
  ::SysFreeString(pbstrFoo);<br />
  pbstrFoo = NULL;<br />
}

Is that about right? So what would a similar calling sequence be for a VB programmer? Is there something I can do differently within my COM object to make it easier for both?

Jason Henderson26-Aug-02 17:01

Jason Henderson

26-Aug-02 17:01

b_p_smith wrote:
BSTR* pbstrFoo = NULL;
MyFunc(pbstrFoo);

You forgot the first param in my example so it would look like this:

BSTR bstrFoo1;
BSTR* pbstrFoo = NULL;
bstrFoo1 = ::SysAllocString(L"Test")
MyFunc(bstrFoo1, pbstrFoo);

In C++ you must free both strings.

I don't use VB so I can't give an example, but when the string falls out of scope, VB should handle freeing the string.

So don't worry about your VB client app, it will just see this as a return value.

Jason Henderson
_{quasi-homepage}
^articles
_{"Like it or not, I'm right!"}