Using BSTR* for Object method of an Automation server

Xavier PILLONS -- 100335.221@compuserve.com
Wednesday, August 28, 1996

Environment:  Win95, VC++ 4.2

When using a BSTR* as a parameter of an OLE Automation server, I have the
following message when calling this method in the client software :
First-chance exception in Client.exe (OLEAUT32.DLL): 0xC0000005: Access
Violation.

Here is the code of the server :
void CServerDoc::GetDataValue(BSTR FAR* lpbstr) 
{
	// TODO: Add your dispatch handler code here
	CString strData1;
	strData1 = "Nom Champ 1";

	*lpbstr = strData1.AllocSysString();
 
}

This method have been created using class wizard.

Here is the code of the client :
	COleServer* pOleServer;
	pOleServer = new COleServer;
	if (!pOleServer)
		return;
		BSTR	bstr1, bstr2;

		pOleServer->GetDataValue(&bstr1); // It hang on this call
		strData1 = bstr1;
		if (bstr1)
			::SysFreeString( bstr1 );

The COleServer class have been imported from the TypeLib using class wizard.

Any help would be appreciate,

Xavier Pillons
SETE Inc.

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Benny -- blee@filenet.com
Friday, August 30, 1996



>>Environment:  Win95, VC++ 4.2
>>
>>When using a BSTR* as a parameter of an OLE Automation server, I have the
>>following message when calling this method in the client software :
>>First-chance exception in Client.exe (OLEAUT32.DLL): 0xC0000005: Access
>>Violation.

I am not positive on this.  Try CoTaskMemFree instead of SysFreeString.  I 
bumped into this problem a while back ago.

Benny

---

Xavier PILLONS -- 100335.221@compuserve.com
Monday, September 02, 1996

I've found my mistake, because of the non initialisation of BSTR pointers. They
must be NULL before calling my OLE method because they are allocated by the OLE
automation.

Thanks for your answer.
Xavier.

----------
Lee Benny wrote :


>>Environment:  Win95, VC++ 4.2
>>
>>When using a BSTR* as a parameter of an OLE Automation server, I have the
>>following message when calling this method in the client software :
>>First-chance exception in Client.exe (OLEAUT32.DLL): 0xC0000005: Access
>>Violation.

I am not positive on this.  Try CoTaskMemFree instead of SysFreeString.  I 
bumped into this problem a while back ago.

Benny

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