字符串转换及UNICODE相关函数

初始化UNICODE字符串
BSTR wcsStr = L"unicode";
_variant_t varString = _T("D:\\sample.xml");
wstring strFindText (_T("author"));

CString To BSTR
CString str = L"aaaaa";
BSTR bs = str.AllocSysString();

UNICODE To CString
CString str = _T("UNICODE字符串");
CString str = _TEXT("UNICODE字符串");

_variant_t To CString
_variant_t var_t;
_bstr_t bstr_t;

bstr_t = var_t;
strValue.Format("%s",(const char *)bstr_t);

_bstr_t To CString
_bstr_t bstr_t;
strValue.Format("%s",(const char *)bstr_t);

相关参考：
http://msdn.microsoft.com/zh-cn/library/ms235631(VS.80).aspx