Windows下字符编码转换

//
//	get current time, yyyyMMddhhmmss
//
char* curtime( char *p, uint len )
{
	if( NULL != p )
	{
		time_t tt;
		time( &tt );
		tm* ptm = localtime( &tt );
		memset( p, 0, sizeof(char) * len );
		sprintf( p, "%d%02d%02d%02d%02d%02d", 1900 + ptm->tm_year, ptm->tm_mon + 1, ptm->tm_mday,
			ptm->tm_hour, ptm->tm_min, ptm->tm_sec );
	}
	return p;
}

//
//	GBK to UTF8
//
char* gbk2utf8( const char *gbk )
{
	if( NULL == gbk )
		return NULL;

	int len = MultiByteToWideChar( CP_ACP, 0, gbk, -1, NULL, 0 );
	WCHAR *pw = new WCHAR[len + 1];
	memset( pw, 0, sizeof(WCHAR) * (len + 1) );
	MultiByteToWideChar( CP_ACP, 0, gbk, -1, pw, len );

	len = WideCharToMultiByte( CP_UTF8, 0, pw, -1, NULL, 0, NULL, NULL );
	char *utf8 = new char[len + 1];
	if( NULL == utf8 )
	{
		delete []pw;
		return NULL;
	}
	memset( utf8, 0, sizeof(char) * (len + 1) );
	WideCharToMultiByte( CP_UTF8, 0, pw, -1, utf8, len, NULL, NULL );

	delete []pw;
	return utf8;
}

//
//	UTF8 to GBK
//
char* utf82gbk( const char *utf8 )
{
	if( NULL == utf8 )
		return NULL;

	int len = MultiByteToWideChar( CP_UTF8, 0, utf8, -1, NULL, 0 );
	WCHAR *pw = new WCHAR[len + 1];
	memset( pw, 0, sizeof(WCHAR) * (len + 1) );
	MultiByteToWideChar( CP_UTF8, 0, utf8, -1, pw, len );

	len = WideCharToMultiByte( CP_ACP, 0, pw, -1, NULL, 0, NULL, NULL );
	char *gbk = new char[len + 1];
	if( NULL == gbk )
	{
		delete []pw;
		return NULL;
	}
	memset( gbk, 0, sizeof(char) * (len + 1) );
	WideCharToMultiByte( CP_ACP, 0, pw, -1, gbk, len, NULL, NULL );

	delete []pw;
	return gbk;
}

//
//	wide char to multy byte
//
char* wc2mb( const WCHAR *wc, int codePage /* = CP_ACP */ )
{
	if( NULL == wc )
		return NULL;
	int n = WideCharToMultiByte( codePage, 0, wc, -1, NULL, 0, NULL, NULL );
	char *p = new char[n + 1];
	memset( p, 0, sizeof(char) * (n + 1) );
	WideCharToMultiByte( codePage, 0, wc, -1, p, n, NULL, NULL );
	return p;
}

//
//	multy byte to wide char
//
WCHAR* mb2wc( const char *mb,  int codePage /* = CP_ACP */ )
{
	if( NULL == mb )
		return NULL;
	int n = MultiByteToWideChar( codePage, 0, mb, -1, NULL, 0 );
	WCHAR *p = new WCHAR[n + 1];
	memset( p, 0, sizeof(WCHAR) * (n + 1) );
	MultiByteToWideChar( codePage, 0, mb, -1, p, n );
	return p;
}

//
//	release buffer
//
void releaseBuffer( char *pbuf )
{
	delete []pbuf;
	pbuf = NULL;
}

注： gbk2utf8、utf82gbk、wc2mb、mb2wc的返回值在使用完成后，需要用releaseBuffer来释放内存，防止内存泄漏。