utf8 ansi unicode 字符相互转化

 

#include "lang.h"
#include <assert.h>
#include <new>
using namespace std;

LPWSTR Utf8ToUnicode(LPSTR lpszUtf8, DWORD& dwBufLen)
{
	assert(lpszUtf8);
	LPWSTR lpwBuf = NULL;

	try
	{
		//得到转换后的字符串长度
		dwBufLen = MultiByteToWideChar(CP_UTF8, 0, lpszUtf8, -1, NULL, NULL);
		
		//new buffer
		lpwBuf = new(nothrow) wchar_t[dwBufLen];
		if (NULL == lpwBuf)
		{
			return NULL;
		}

		memset(lpwBuf, 0, dwBufLen * sizeof(wchar_t));
	
		MultiByteToWideChar(CP_UTF8, 0, lpszUtf8, -1, lpwBuf, dwBufLen);
	}
	catch (...)
	{
		return NULL;
	}

	return lpwBuf;	
}

LPSTR UnicodeToUtf8(LPWSTR lpwBuf, DWORD& dwBufLen)
{
	assert(lpwBuf);
	LPSTR lpszUtf8 = NULL;

	try
	{
		//得到转换后的字符串长度
		dwBufLen = WideCharToMultiByte(CP_UTF8, 0, lpwBuf, -1, NULL, 0, NULL, NULL);

		lpszUtf8 = new(nothrow) char[dwBufLen];
		if (NULL == lpszUtf8)
		{
			return lpszUtf8;
		}

		memset(lpszUtf8, 0, dwBufLen);

		WideCharToMultiByte(CP_UTF8, 0, lpwBuf, -1, lpszUtf8, dwBufLen, NULL, NULL);
	}
	catch (...)
	{
		return NULL;
	}

	return lpszUtf8;
}

LPSTR UnicodeToAnsi(LPWSTR lpwBuf, DWORD& dwBufLen)
{
	assert(lpwBuf);
	LPSTR lpszBuf = NULL;

	try
	{
		//得到转换后的字符串长度
		dwBufLen = WideCharToMultiByte(CP_ACP, 0, lpwBuf, -1, NULL, 0, NULL, NULL);

		lpszBuf = new(nothrow) char[dwBufLen];
		if (NULL == lpszBuf)
		{
			return lpszBuf;
		}

		memset(lpszBuf, 0, dwBufLen);

		WideCharToMultiByte(CP_ACP, 0, lpwBuf, -1, lpszBuf, dwBufLen, NULL, NULL);
	}
	catch (...)
	{
		return NULL;
	}

	return lpszBuf;
}


LPWSTR AnsiToUnicode(LPSTR lpszBuf, DWORD& dwBufLen)
{
	assert(lpszBuf);
	LPWSTR lpwBuf = NULL;

	try
	{
		dwBufLen = MultiByteToWideChar(CP_ACP, 0, lpszBuf, -1, NULL, 0);
		//new buffer
		lpwBuf = new(nothrow) wchar_t[dwBufLen];
		if (NULL == lpwBuf)
		{
			return NULL;
		}

		memset(lpwBuf, 0, dwBufLen * sizeof(wchar_t));

		MultiByteToWideChar(CP_ACP, 0, lpszBuf, -1, lpwBuf, dwBufLen);
	}
	catch (...)
	{
		return NULL;
	}
	
	return lpwBuf;
}

LPSTR AnsiToUtf8(LPSTR lpszBuf, DWORD& dwBufLen)
{
	assert(lpszBuf);
	LPSTR lpszUtf8 = NULL;

	try
	{
		LPWSTR lpwBuf = AnsiToUnicode(lpszBuf, dwBufLen);
		if (NULL == lpwBuf)
		{
			return NULL;
		}

		lpszUtf8 = UnicodeToUtf8(lpwBuf, dwBufLen);

		//release
		delete[] lpwBuf;
		lpwBuf = NULL;
	}
	catch (...)
	{
		return NULL;
	}

	return lpszUtf8;
}

LPSTR Utf8ToAnsi(LPSTR lpszUtf8, DWORD& dwBufLen)
{
	assert(lpszUtf8);
	LPSTR lpszBuf = NULL;

	try
	{
		LPWSTR lpwBuf = Utf8ToUnicode(lpszUtf8, dwBufLen);
		if (NULL == lpwBuf)
		{
			return NULL;
		}

		lpszBuf = UnicodeToAnsi(lpwBuf, dwBufLen);

		//release buff
		delete[] lpwBuf;
		lpwBuf = NULL;
	}
	catch (...)
	{
		return NULL;
	}

	return lpszBuf;
}