ansi编码和utf8相互转换

1、windows平台下

#ifdef _WIN32


int CParserIni::ansi2utf8(const string& ansiStr, string& utf8Str)
{
int ret = kNoError;
do{
//CP_ACP(ANSI字符集）
if (ansiStr.empty()) BREAK_WITH_ERROR(kInvalidParameter);
//现将本地代码页转换成utf16
int wlen = MultiByteToWideChar(CP_ACP, 0, ansiStr.c_str(), -1, NULL, 0);
if (wlen == 0) BREAK_WITH_ERROR(kConvertError);
wchar_t *pwBuf = new wchar_t[wlen + 1];
memset(pwBuf, 0, sizeof(wchar_t)*(wlen + 1));
if (MultiByteToWideChar(CP_ACP, 0, ansiStr.c_str(), ansiStr.length(), pwBuf, wlen)==0)
BREAK_WITH_ERROR(kConvertError);
//再将utf16转换utf8
int len = WideCharToMultiByte(CP_UTF8, 0, pwBuf, -1, NULL, NULL, NULL, NULL);
if (len == 0) BREAK_WITH_ERROR(kConvertError);
char *pBuf = new char[len + 1];
memset(pBuf, 0, len + 1);
if (WideCharToMultiByte(CP_UTF8, 0, pwBuf, wlen, pBuf, len, NULL, NULL) == 0)
BREAK_WITH_ERROR(kConvertError);


utf8Str = pBuf;
delete pwBuf;
delete pBuf;
pwBuf = NULL;
pBuf = NULL;




} while (0);


return ret;
}


int CParserIni::utf82ansi(const string& utf8Str, string& ansiStr)
{
int ret = kNoError;


do{
//将utf8转成utf16（wchar_t)
if (utf8Str.empty()) BREAK_WITH_ERROR(kInvalidParameter);
int wlen = MultiByteToWideChar(CP_UTF8, 0, utf8Str.c_str(), -1, NULL, NULL);
if (wlen == 0) BREAK_WITH_ERROR(kConvertError);
wchar_t *pwBuf = new wchar_t[wlen + 1];
memset(pwBuf, 0, sizeof(wchar_t)*(wlen + 1));
if (MultiByteToWideChar(CP_UTF8, 0, utf8Str.c_str(), utf8Str.length(), pwBuf, wlen) == 0)
BREAK_WITH_ERROR(kConvertError);


//将wchar_t转换成ANSI
int len = WideCharToMultiByte(CP_ACP, 0, pwBuf, -1, NULL, NULL, NULL, NULL);
if (len == 0) BREAK_WITH_ERROR(kConvertError);
char *pBuf = new char[len + 1];
memset(pBuf, 0, len + 1);
if (WideCharToMultiByte(CP_ACP, 0, pwBuf, wlen, pBuf, len, NULL, NULL)==0)
BREAK_WITH_ERROR(kConvertError);

ansiStr = pBuf;
delete pwBuf;
delete pBuf;
pwBuf = NULL;
pwBuf = NULL;


} while (0);


return ret;
}

#endif

#ifdef _WIN32

int CParserIni::ansi2utf8(const string& ansiStr, string& utf8Str)
{
	int ret = kNoError;

	do{
		//CP_ACP(ANSI字符集）
		if (ansiStr.empty())	BREAK_WITH_ERROR(kInvalidParameter);
		//现将本地代码页转换成utf16
		int wlen = MultiByteToWideChar(CP_ACP, 0, ansiStr.c_str(), -1, NULL, 0);
		if (wlen == 0)	BREAK_WITH_ERROR(kConvertError);
		wchar_t *pwBuf = new wchar_t[wlen + 1];
		memset(pwBuf, 0, sizeof(wchar_t)*(wlen + 1));
		if (MultiByteToWideChar(CP_ACP, 0, ansiStr.c_str(), ansiStr.length(), pwBuf, wlen)==0)
			BREAK_WITH_ERROR(kConvertError);
		//再将utf16转换utf8
		int len = WideCharToMultiByte(CP_UTF8, 0, pwBuf, -1, NULL, NULL, NULL, NULL);
		if (len == 0) BREAK_WITH_ERROR(kConvertError);
		char *pBuf = new char[len + 1];
		memset(pBuf, 0, len + 1);
		if (WideCharToMultiByte(CP_UTF8, 0, pwBuf, wlen, pBuf, len, NULL, NULL) == 0)	
			BREAK_WITH_ERROR(kConvertError);

		utf8Str = pBuf;
		delete pwBuf;
		delete pBuf;
		pwBuf = NULL;
		pBuf = NULL;
		
		

	} while (0);

	return ret;
}

int CParserIni::utf82ansi(const string& utf8Str, string& ansiStr)
{
	int ret = kNoError;

	do{
		//将utf8转成utf16（wchar_t)
		if (utf8Str.empty()) BREAK_WITH_ERROR(kInvalidParameter);
		int wlen = MultiByteToWideChar(CP_UTF8, 0, utf8Str.c_str(), -1, NULL, NULL);
		if (wlen == 0)	BREAK_WITH_ERROR(kConvertError);
		wchar_t *pwBuf = new wchar_t[wlen + 1];
		memset(pwBuf, 0, sizeof(wchar_t)*(wlen + 1));
		if (MultiByteToWideChar(CP_UTF8, 0, utf8Str.c_str(), utf8Str.length(), pwBuf, wlen) == 0)
			BREAK_WITH_ERROR(kConvertError);

		//将wchar_t转换成ANSI
		int len = WideCharToMultiByte(CP_ACP, 0, pwBuf, -1, NULL, NULL, NULL, NULL);
		if (len == 0)	BREAK_WITH_ERROR(kConvertError);
		char *pBuf = new char[len + 1];
		memset(pBuf, 0, len + 1);
		if (WideCharToMultiByte(CP_ACP, 0, pwBuf, wlen, pBuf, len, NULL, NULL)==0)
			BREAK_WITH_ERROR(kConvertError);
		
		ansiStr = pBuf;
		delete pwBuf;
		delete pBuf;
		pwBuf = NULL;
		pwBuf = NULL;

	} while (0);

	return ret;
}

#endif

2、linux平台下

mbstowcs() 
wcstombs()