COM Converting BSTR to CString and CString to BSTR, another CComBSTR, LPCTSTR, _bstr_t

C Language String Types and Classes

String Type	Description
char/wchar/TCHAR	The C strings for ANSI and Unicode
CString	The C++/MFC class wrapper for C strings
BSTR	The Visual Basic string type
_bstr_t	A C++ class wrapper for the Visual Basic string type
CComBSTR	Yet another C++ class wrapper for the Visual Basic string type used predominately in ATL code

 

Demo Code

 

BSTR to CString and CString to BSTR

 

void BSTRtoCString(BSTR bStr){     CString csStr =bStr; } void CStringtoBSTR() {     CString csStr = NULL;     csStr = "Hello BelieveIT!";     BSTR bStr = csStr.AllocSysString();     BSTRtoCString(bStr);     ::SysFreeString(bStr); //finished using the BSTR }

 

Base Code

BSTR GetBSTR() {     _bstr_t bstrt(_T("This is the test string!"));     BSTR bstr;     bstr = bstrt.copy();     return bstr; } CComBSTR GetComBSTR() {     CComBSTR bstr("This is the test string!");     return bstr; } void ShowBSTR(BSTR bstr) {     _bstr_t bstrt(bstr);     CString cstr;     cstr.Format(_T("%s"),(LPCTSTR)bstrt);     AfxMessageBox(cstr); }

 

Conversions Code

 

_bstr_t BSTRto_bstr_t() {     BSTR bstr = GetBSTR();     _bstr_t bstrFinal(bstr);     ShowBSTR(bstrFinal);     bstrFinal = bstr;     return bstrFinal; }   BSTR _bstr_ttoBSTR() {     _bstr_t bstr(_T("This is Converting string"));     BSTR bstrFinish;     bstrFinish = bstr.copy();     ShowBSTR(bstrFinish);     bstrFinish = bstr;     return bstrFinish; }   BSTR CComBSTRtoBSTR() {     CComBSTR bstr(_T("This is Converting string"));     BSTR bstrFinish;     bstrFinish = bstr;     ShowBSTR(bstrFinish);     bstrFinish = bstr.Copy();     return bstrFinish; }   CComBSTR _bstr_ttoCComBSTR() {     _bstr_t bstr(_T("This is Converting string"));     CComBSTR bstrFinish;     bstrFinish.AppendBSTR(bstr);     return bstrFinish; }   CString BSTRtoCString() {     //conversion that only works in Unicode     BSTR bstr;     bstr = GetBSTR();     TCHAR szFinal[255] = {0,};     _stprintf(szFinal, _T("%s"), (LPCTSTR)bstr);     AfxMessageBox(szFinal);     _bstr_t bstrIntermediate(bstr);     CString strFinal;     _stprintf(szFinal, _T("%s"), (LPCTSTR)bstrIntermediate);     strFinal.Format(_T("%s"),(LPCTSTR)bstrIntermediate);     return strFinal; }   CString _bstr_ttoCString() {     _bstr_t bstr(_T("This is Converting string"));     TCHAR szFinal[255] = {0,};     _stprintf(szFinal,_T("%s"),(LPCTSTR)bstr);     return szFinal; }   LPCTSTR CComBSTRtoLPCTSTR() {     CComBSTR bstr("This is Converting string");     _bstr_t bstrIntermediate(bstr);     TCHAR szFinal[255] = {0,};     _stprintf(szFinal, _T("%s"),(LPCTSTR)bstrIntermediate);     return szFinal; }   _bstr_t LPCTSTRto_bstr_t() {     LPCTSTR szStart = _T("This is Converting string");     _bstr_t bstrFinal(szStart);     ShowBSTR(bstrFinal);     bstrFinal = szStart;     return bstrFinal; }   CComBSTR LPCTSTRtoComBSTR() {     LPCTSTR szStart = _T("This is Converting string");     CComBSTR bstrFinal(szStart);     ShowBSTR(bstrFinal);     bstrFinal.Empty();     bstrFinal.Append(szStart);     return bstrFinal; }

 

[ Reference ]

http://blog.naver.com/mismir?Redirect=Log&logNo=40013446819

http://www.codeproject.com/Articles/1282/Easy-way-to-manipulate-BSTR-using-CString-class