多字节与UTF-8、Unicode之间的转换

from http://blog.csdn.net/frankiewang008/article/details/12832239

// 多字节编码转为UTF8编码
bool MBToUTF8(vector<char>& pu8, const char* pmb, int32 mLen)
{
 // convert an MBCS string to widechar
 int32 nLen = MultiByteToWideChar(CP_ACP, 0, pmb, mLen, NULL, 0);

 WCHAR* lpszW = NULL;
 try
 {
    lpszW = new WCHAR[nLen];
 }
 catch(bad_alloc &memExp)
 {
    return false;
 }

 int32 nRtn = MultiByteToWideChar(CP_ACP, 0, pmb, mLen, lpszW, nLen);

 if(nRtn != nLen)
 {
    delete[] lpszW;
    return false;
 }
 // convert an widechar string to utf8
 int32 utf8Len = WideCharToMultiByte(CP_UTF8, 0, lpszW, nLen, NULL, 0, NULL, NULL);
 if (utf8Len <= 0)
 {
     return false;
 }
 pu8.resize(utf8Len);
 nRtn = WideCharToMultiByte(CP_UTF8, 0, lpszW, nLen, &*pu8.begin(), utf8Len, NULL, NULL);
 delete[] lpszW;

 if (nRtn != utf8Len)
 {
     pu8.clear();
     return false;
 }
 return true;
}

// UTF8编码转为多字节编码
bool UTF8ToMB(vector<char>& pmb, const char* pu8, int32 utf8Len)
{
    // convert an UTF8 string to widechar
    int32 nLen = MultiByteToWideChar(CP_UTF8, 0, pu8, utf8Len, NULL, 0);

    WCHAR* lpszW = NULL;
    try
    {
        lpszW = new WCHAR[nLen];
    }
    catch(bad_alloc &memExp)
    {
        return false;
    }

    int32 nRtn = MultiByteToWideChar(CP_UTF8, 0, pu8, utf8Len, lpszW, nLen);

    if(nRtn != nLen)
    {
        delete[] lpszW;
        return false;
    }

    // convert an widechar string to Multibyte
    int32 MBLen = WideCharToMultiByte(CP_ACP, 0, lpszW, nLen, NULL, 0, NULL, NULL);
    if (MBLen <=0)
    {
        return false;
    }
    pmb.resize(MBLen);
    nRtn = WideCharToMultiByte(CP_ACP, 0, lpszW, nLen, &*pmb.begin(), MBLen, NULL, NULL);
    delete[] lpszW;

    if(nRtn != MBLen)
    {
        pmb.clear();
        return false;
    }
    return true;
}

// 多字节编码转为Unicode编码
bool MBToUnicode(vector<wchar_t>& pun, const char* pmb, int32 mLen)
{
    // convert an MBCS string to widechar
    int32 uLen = MultiByteToWideChar(CP_ACP, 0, pmb, mLen, NULL, 0);

    if (uLen<=0)
    {
        return false;
    }
    pun.resize(uLen);

    int32 nRtn = MultiByteToWideChar(CP_ACP, 0, pmb, mLen, &*pun.begin(), uLen);

    if (nRtn != uLen)
    {
        pun.clear();
        return false;
    }
    return true;
}

//Unicode编码转为多字节编码
bool UnicodeToMB(vector<char>& pmb, const wchar_t* pun, int32 uLen)
{
    // convert an widechar string to Multibyte
    int32 MBLen = WideCharToMultiByte(CP_ACP, 0, pun, uLen, NULL, 0, NULL, NULL);
    if (MBLen <=0)
    {
        return false;
    }
    pmb.resize(MBLen);
    int nRtn = WideCharToMultiByte(CP_ACP, 0, pun, uLen, &*pmb.begin(), MBLen, NULL, NULL);

    if(nRtn != MBLen)
    {
        pmb.clear();
        return false;
    }
    return true;
}

// UTF8编码转为Unicode
bool UTF8ToUnicode(vector<wchar_t>& pun, const char* pu8, int32 utf8Len)
{
    // convert an UTF8 string to widechar
    int32 nLen = MultiByteToWideChar(CP_UTF8, 0, pu8, utf8Len, NULL, 0);
    if (nLen <=0)
    {
        return false;
    }
    pun.resize(nLen);
    int32 nRtn = MultiByteToWideChar(CP_UTF8, 0, pu8, utf8Len, &*pun.begin(), nLen);

    if(nRtn != nLen)
    {
        pun.clear();
        return false;
    }

    return true;
}

// Unicode编码转为UTF8
bool UnicodeToUTF8(vector<char>& pu8, const wchar_t* pun, int32 uLen)
{
    // convert an widechar string to utf8
    int32 utf8Len = WideCharToMultiByte(CP_UTF8, 0, pun, uLen, NULL, 0, NULL, NULL);
    if (utf8Len<=0)
    {
        return false;
    }
    pu8.resize(utf8Len);
    int32 nRtn = WideCharToMultiByte(CP_UTF8, 0, pun, uLen, &*pu8.begin(), utf8Len, NULL, NULL);

    if (nRtn != utf8Len)
    {
        pu8.clear();
        return false;
    }
    return true;
}