GBK兼容GB2312，同时在GB2312标准的基础上扩展了GB13000包含的字。

CComVar CComVar::ToGBK(const char * strUtf8 ) {	int len=MultiByteToWideChar(CP_UTF8, 0, strUtf8, -1, NULL,0);	LPWSTR wszGBK = new WCHAR[len+1];	memset(wszGBK, 0, len * 2 + 2);	MultiByteToWideChar(CP_UTF8, 0, strUtf8, -1, wszGBK, len);	CComVar mVar(wszGBK);	delete[] wszGBK;	return mVar;}std::string CComVar::ToUTF8() const{	std::string strTemp = ToString();	int len=MultiByteToWideChar(CP_ACP, 0, strTemp.c_str(), -1, NULL,0);	//unsigned short * wszUtf8 = new unsigned short[len+1];	WCHAR* wszUtf8 = new WCHAR[len+1];  	memset(wszUtf8, 0, len * 2 + 2);	MultiByteToWideChar(CP_ACP, 0, strTemp.c_str(), -1, wszUtf8, len);	len = WideCharToMultiByte(CP_UTF8, 0, wszUtf8, -1, NULL, 0, NULL, NULL);	char *szUtf8=new char[len + 1];	memset(szUtf8, 0, len + 1);	WideCharToMultiByte (CP_UTF8, 0, wszUtf8, -1, szUtf8, len, NULL,NULL);	std::string mVar(szUtf8);	delete[] szUtf8;	delete[] wszUtf8;	return mVar;}