跨平台：utf8与Unicode、string与wstring相互转换【经验】

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/*******************************************************    函数名称：UTF2Uni    函数功能：utf-8转Unicode（跨平台）    输入参数：        src：utf-8编码格式的字符指针        t：Unicode编码格式的宽字符串    输出参数：无    返 回 值：0表示执行成功*******************************************************/int UTF2Uni(const char* src, std::wstring &t){    if (src == NULL)     {        return -1;    }    int size_s = strlen(src);    int size_d = size_s * 2;             wchar_t *des = new wchar_t[size_d];    memset(des, 0, size_d * sizeof(wchar_t));    int s = 0, d = 0;    //设为true时，跳过错误前缀    bool toomuchbyte = true;     while (s < size_s && d < size_d)    {        unsigned char c = src[s];        if ((c & 0x80) == 0)         {            des[d++] += src[s++];        }         else if((c & 0xE0) == 0xC0)  ///< 110x-xxxx 10xx-xxxx        {            WCHAR &wideChar = des[d++];            wideChar  = (src[s + 0] & 0x3F) << 6;            wideChar |= (src[s + 1] & 0x3F);            s += 2;        }        else if((c & 0xF0) == 0xE0)  ///< 1110-xxxx 10xx-xxxx 10xx-xxxx        {            WCHAR &wideChar = des[d++];            wideChar  = (src[s + 0] & 0x1F) << 12;            wideChar |= (src[s + 1] & 0x3F) << 6;            wideChar |= (src[s + 2] & 0x3F);            s += 3;        }         else if((c & 0xF8) == 0xF0)  ///< 1111-0xxx 10xx-xxxx 10xx-xxxx 10xx-xxxx         {            WCHAR &wideChar = des[d++];            wideChar  = (src[s + 0] & 0x0F) << 18;            wideChar  = (src[s + 1] & 0x3F) << 12;            wideChar |= (src[s + 2] & 0x3F) << 6;            wideChar |= (src[s + 3] & 0x3F);            s += 4;        }         else         {            WCHAR &wideChar = des[d++]; ///< 1111-10xx 10xx-xxxx 10xx-xxxx 10xx-xxxx 10xx-xxxx             wideChar  = (src[s + 0] & 0x07) << 24;            wideChar  = (src[s + 1] & 0x3F) << 18;            wideChar  = (src[s + 2] & 0x3F) << 12;            wideChar |= (src[s + 3] & 0x3F) << 6;            wideChar |= (src[s + 4] & 0x3F);            s += 5;        }    }    t = des;    delete[] des;    des = NULL;    return 0;} /*******************************************************    函数名称：Uni2UTF    函数功能：Unicode转utf-8（跨平台）    输入参数：        wchar：Unicode编码格式的宽字符数组        utf8：utf-8编码格式的字符指针    输出参数：无    返 回 值：utf-8编码格式的字符指针长度*******************************************************/int Uni2UTF(wchar_t wchar, char *utf8){    if (utf8 == NULL) {        return -1;    }    int len = 0;    int size_d = 8;    if (wchar < 0x80)    {  //        //length = 1;        utf8[len++] = (char)wchar;    }    else if(wchar < 0x800)    {        //length = 2;        if (len + 1 >= size_d)            return -1;        utf8[len++] = 0xc0 | ( wchar >> 6 );        utf8[len++] = 0x80 | ( wchar & 0x3f );    }    else if(wchar < 0x10000 )    {        //length = 3;        if (len + 2 >= size_d)            return -1;        utf8[len++] = 0xe0 | ( wchar >> 12 );        utf8[len++] = 0x80 | ( (wchar >> 6) & 0x3f );        utf8[len++] = 0x80 | ( wchar & 0x3f );    }    else if( wchar < 0x200000 )     {        //length = 4;        if (len + 3 >= size_d)            return -1;        utf8[len++] = 0xf0 | ( (int)wchar >> 18 );        utf8[len++] = 0x80 | ( (wchar >> 12) & 0x3f );        utf8[len++] = 0x80 | ( (wchar >> 6) & 0x3f );        utf8[len++] = 0x80 | ( wchar & 0x3f );    }    return len;}/*******************************************************    函数名称：s2ws    函数功能：string转wstring（跨平台），不涉及编码格式的转换    输入参数：        s：Unicode编码格式的string    输出参数：无    返 回 值：Unicode编码格式的wstring*******************************************************/std::wstring s2ws(const std::string& s){    #if (defined WIN32) ||  (defined _WIN32)          setlocale(LC_ALL,"chs");      #else          setlocale(LC_ALL,"zh_CN.gbk");      #endif    const char* _Source = s.c_str();    size_t _Dsize = s.size() + 1;    wchar_t *_Dest = new wchar_t[_Dsize];    wmemset(_Dest, 0, _Dsize);    mbstowcs(_Dest,_Source,_Dsize);    std::wstring result = _Dest;    delete []_Dest;    setlocale(LC_ALL, "C");    return result;}/*******************************************************    函数名称：ws2s    函数功能：wstring转string（跨平台），不涉及编码格式的转换    输入参数：        ws：Unicode编码格式的wstring    输出参数：无    返 回 值：Unicode编码格式的string*******************************************************/std::string ws2s(const std::wstring& ws){    std::string curLocale = setlocale(LC_ALL, NULL);     #if (defined WIN32) ||  (defined _WIN32)          setlocale(LC_ALL,"chs");      #else          setlocale(LC_ALL,"zh_CN.gbk");      #endif     const wchar_t* _Source = ws.c_str();    size_t _Dsize = 2 * ws.size() + 1;    char *_Dest = new char[_Dsize];    memset(_Dest,0,_Dsize);    wcstombs(_Dest,_Source,_Dsize);    std::string result = _Dest;    delete []_Dest;    setlocale(LC_ALL, curLocale.c_str());    return result;}