C++ UTF8 互转 Unicode

C++/MFC   UTF8 转 Unicode

char* U8ToUnicode(char* szU8)
{
    //UTF8 to Unicode
    //预转换，得到所需空间的大小
    int wcsLen = ::MultiByteToWideChar(CP_UTF8, NULL, szU8, strlen(szU8), NULL, 0);
    //分配空间要给'\0'留个空间，MultiByteToWideChar不会给'\0'空间
    wchar_t* wszString = new wchar_t[wcsLen + 1];
    //转换
    ::MultiByteToWideChar(CP_UTF8, NULL, szU8, strlen(szU8), wszString, wcsLen);
    //最后加上'\0'
    wszString[wcsLen] = '\0';

    char *m_char;
    int len = WideCharToMultiByte(CP_ACP, 0, wszString, wcslen(wszString), NULL, 0, NULL, NULL);
    m_char = new char[len + 1];
    WideCharToMultiByte(CP_ACP, 0, wszString, wcslen(wszString), m_char, len, NULL, NULL);
    m_char[len] = '\0';
    return m_char;
}

Unicode 转  UTF8

char* UnicodeToU8(wchar_t* wszString)
{
    // unicode to UTF8
    //预转换，得到所需空间的大小，这次用的函数和上面名字相反
    int u8Len = ::WideCharToMultiByte(CP_UTF8, NULL, wszString, wcslen(wszString), NULL, 0, NULL, NULL);
    //同上，分配空间要给'\0'留个空间
    //UTF8虽然是Unicode的压缩形式，但也是多字节字符串，所以可以以char的形式保存
    char* szU8 = new char[u8Len + 1];
    //转换
    //unicode版对应的strlen是wcslen
    ::WideCharToMultiByte(CP_UTF8, NULL, wszString, wcslen(wszString), szU8, u8Len, NULL, NULL);
    //最后加上'\0'
    szU8[u8Len] = '\0';
    return szU8;
}