轉自：http://blog.sina.com.cn/s/blog_81084a3a01014srq.html

healer_kxinline std::string KS_UTF8_to_ANSI (const char* szUTF8)
{
    if (szUTF8 == NULL)
        return "" ;
    
    int     nLen = ::MultiByteToWideChar (CP_UTF8, 0, szUTF8, -1, NULL, 0) ;
    WCHAR   * pWstr = new WCHAR[nLen+1] ;
    ZeroMemory (pWstr, sizeof(WCHAR) * (nLen+1)) ;
    ::MultiByteToWideChar (CP_UTF8, 0, szUTF8, -1, pWstr, nLen) ;
    std::string     strAnsi (_bstr_t((wchar_t*)pWstr)) ;
    delete[] pWstr ;
    return strAnsi ;
}

inline char* KS_ANSI_to_UTF8 (const char* szAnsi)
{
    if (szAnsi == NULL)
        return NULL ;
    
    _bstr_t   bstrTmp (szAnsi) ;
    int       nLen = ::WideCharToMultiByte (CP_UTF8, 0, (LPCWSTR)bstrTmp, -1, NULL, 0, NULL, NULL) ;
    char      * pUTF8 = new char[nLen+1] ;
    ZeroMemory (pUTF8, nLen + 1) ;
    ::WideCharToMultiByte (CP_UTF8, 0, (LPCWSTR)bstrTmp, -1, pUTF8, nLen, NULL, NULL) ;
    return pUTF8 ;
}