1 Windows/Linux跨平台gbk与utf8字符集编码转换

在Windows系统上使用系统api，在linux上使用iconv进行gbk与utf8字符集编码转换

我已经将上述功能封装为single header的工具类，具体代码如下

#ifndef _CHARACTERSET_CONVERT_H_
#define _CHARACTERSET_CONVERT_H_

#include <string>

#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__)

#include <Windows.h>

#elif defined(linux) || defined(__linux)

#include <iconv.h>
#include <malloc.h>

#endif

namespace stubbornhuang
{
    class CharactersetConvert
    {
    public:
#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__)
        static std::string gbk_to_utf8(const std::string& gbk_str)
        {
            int len = MultiByteToWideChar(CP_ACP, 0, gbk_str.c_str(), -1, NULL, 0);
            wchar_t* wstr = new wchar_t[len + 1];
            memset(wstr, 0, len + 1);
            MultiByteToWideChar(CP_ACP, 0, gbk_str.c_str(), -1, wstr, len);
            len = WideCharToMultiByte(CP_UTF8, 0, wstr, -1, NULL, 0, NULL, NULL);
            char* str = new char[len + 1];
            memset(str, 0, len + 1);
            WideCharToMultiByte(CP_UTF8, 0, wstr, -1, str, len, NULL, NULL);
            std::string strTemp = str;
            if (wstr) delete[] wstr;
            if (str) delete[] str;
            return strTemp;
        }

        static std::string utf8_to_gbk(const std::string& utf8_str)
        {
            int len = MultiByteToWideChar(CP_UTF8, 0, utf8_str.c_str(), -1, NULL, 0);
            wchar_t* wszGBK = new wchar_t[len + 1];
            memset(wszGBK, 0, len * 2 + 2);
            MultiByteToWideChar(CP_UTF8, 0, utf8_str.c_str(), -1, wszGBK, len);
            len = WideCharToMultiByte(CP_ACP, 0, wszGBK, -1, NULL, 0, NULL, NULL);
            char* szGBK = new char[len + 1];
            memset(szGBK, 0, len + 1);
            WideCharToMultiByte(CP_ACP, 0, wszGBK, -1, szGBK, len, NULL, NULL);
            std::string strTemp(szGBK);
            if (wszGBK) delete[] wszGBK;
            if (szGBK) delete[] szGBK;
            return strTemp;
        }

#elif defined(linux) || defined(__linux)
        static int code_convert(
            const char* from_charset, 
            const char* to_charset, 
            char* inbuf, size_t inlen,
            char* outbuf, size_t outlen
        ) {
            iconv_t cd;
            char** pin = &inbuf;
            char** pout = &outbuf;

            cd = iconv_open(to_charset, from_charset);
            if (cd == 0)
                return -1;

            memset(outbuf, 0, outlen);

            if ((int)iconv(cd, pin, &inlen, pout, &outlen) == -1)
            {
                iconv_close(cd);
                return -1;
            }
            iconv_close(cd);
            *pout = '\0';

            return 0;
        }

        static int u2g(char* inbuf, size_t inlen, char* outbuf, size_t outlen) {
            return code_convert("utf-8", "gb2312", inbuf, inlen, outbuf, outlen);
        }

        static int g2u(char* inbuf, size_t inlen, char* outbuf, size_t outlen) {
            return code_convert("gb2312", "utf-8", inbuf, inlen, outbuf, outlen);
        }


        static std::string gbk_to_utf8(const std::string& gbk_str)
        {
            int length = gbk_str.size() * 2 + 1;

            char* temp = (char*)malloc(sizeof(char) * length);

            if (g2u((char*)gbk_str.c_str(), gbk_str.size(), temp, length) >= 0)
            {
                std::string str_result;
                str_result.append(temp);
                free(temp);
                return str_result;
    }
            else
            {
                free(temp);
                return "";
            }
        }

        static std::string utf8_to_gbk(const std::string& utf8_str)
        {
            int length = strlen(utf8_str);

            char* temp = (char*)malloc(sizeof(char) * length);

            if (u2g((char*)utf8_str, length, temp, length) >= 0)
            {
                std::string str_result;
                str_result.append(temp);
                free(temp);

                return str_result;
            }
            else
            {
                free(temp);
                return "";
            }
        }

#endif

    };
}

#endif // !_CHARACTERSET_CONVERT_H_

使用示例

#include <iostream>
#include "CharactersetConvert.h"

using namespace std;

int main()
{
    std::string nihao = "你好";

    std::string nihao_utf8 = stubbornhuang::CharactersetConvert::gbk_to_utf8(nihao);

    std::cout << nihao_utf8 << std::endl;

    std::string nihao_gbk = stubbornhuang::CharactersetConvert::utf8_to_gbk(nihao_utf8);

    std::cout << nihao_gbk << std::endl;

    return 0;
}

参考链接