what is equivalent to _bstr_t?

Hi,

I have a COM DLL I wrote in C# which I call from one of my MFC applications as follows:

Code:

---

BOOL CDADcb::OpenDatabase( CString strFilename )
{
   BSTR bstrName = strFilename.AllocSysString();
   m_bLoaded = m_spDCBParse->OpenDatabase( bstrName );
   return m_bLoaded;
}

---

My problem is, what data type do I use as the BSTR using Qt4?

Kind regards,
Steve

Quote:

---

Originally Posted by steg90

Hi,

I have a COM DLL I wrote in C# which I call from one of my MFC applications as follows:

Code:

---

BOOL CDADcb::OpenDatabase( CString strFilename )
{
   BSTR bstrName = strFilename.AllocSysString();
   m_bLoaded = m_spDCBParse->OpenDatabase( bstrName );
   return m_bLoaded;
}

---

My problem is, what data type do I use as the BSTR using Qt4?

Kind regards,
Steve

---

By seeing your code, I think strFilename.AllocSysString() return QCString. Since there is no QCString in Qt4 you can use QByteArray. See qtassistance for more information.

Hi,

The AllocSysString returns a BSTR, but there doesn't seem to be an equivalent in Qt4? The code I'm showing is for MFC. I just want to know how I can call the OpenDatabase function which takes a _bstr_t data type, I don't know what the equivalent is in Qt.

Regards,
Steve

Quote:

---

Originally Posted by steg90

Hi,

The AllocSysString returns a BSTR, but there doesn't seem to be an equivalent in Qt4? The code I'm showing is for MFC. I just want to know how I can call the OpenDatabase function which takes a _bstr_t data type, I don't know what the equivalent is in Qt.

Regards,
Steve

---

What is BSTR??? What is the return type??

Hi,

BSTR is OLECHAR*

I have just done the following which works :

Code:

---

BOOL CDADcb::OpenDatabase( CString strFilename )
{
	m_bLoaded = FALSE;
	BSTR s = SysAllocString( (OLECHAR*)strFilename.unicode() );
	m_bLoaded = m_spDCBParse->OpenDatabase( s );//strFilename );
	SysFreeString( s );
	return m_bLoaded;
}

---

Regards,
Steve

Why not use the same type as in other C++ apps? You don't have to use Qt classes everywhere...