C++实现utf8和gbk编码字符串互相转换

不同系统或者服务器之间消息传递经常遇到编码转换问题，这里用C++实现了一个轻量的gbk和utf8互相转换，可跨平台使用。（重量级的可以用libiconv库）

在windows下用<windows.h>头文件里的函数进行多字节和宽字符转换，linux下采用<iconv.h>头文件里的函数进行编码互相解析。

代码

#include <iostream>
#include <string>
#include <string.h>
#include <stdlib.h>using namespace std;#ifdef _WIN32
#include <windows.h>string GbkToUtf8(const char *src_str)
{int len = MultiByteToWideChar(CP_ACP, 0, src_str, -1, NULL, 0);wchar_t* wstr = new wchar_t[len + 1];memset(wstr, 0, len + 1);MultiByteToWideChar(CP_ACP, 0, src_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);string strTemp = str;if (wstr) delete[] wstr;if (str) delete[] str;return strTemp;
}string Utf8ToGbk(const char *src_str)
{int len = MultiByteToWideChar(CP_UTF8, 0, src_str, -1, NULL, 0);wchar_t* wszGBK = new wchar_t[len + 1];memset(wszGBK, 0, len * 2 + 2);MultiByteToWideChar(CP_UTF8, 0, src_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);string strTemp(szGBK);if (wszGBK) delete[] wszGBK;if (szGBK) delete[] szGBK;return strTemp;
}
#else
#include <iconv.h>int GbkToUtf8(char *str_str, size_t src_len, char *dst_str, size_t dst_len)
{iconv_t cd;char **pin = &str_str;char **pout = &dst_str;cd = iconv_open("utf8", "gbk");if (cd == 0)return -1;memset(dst_str, 0, dst_len);if (iconv(cd, pin, &src_len, pout, &dst_len) == -1)return -1;iconv_close(cd);*pout = '\0';return 0;
}int Utf8ToGbk(char *src_str, size_t src_len, char *dst_str, size_t dst_len)
{iconv_t cd;char **pin = &src_str;char **pout = &dst_str;cd = iconv_open("gbk", "utf8");if (cd == 0)return -1;memset(dst_str, 0, dst_len);if (iconv(cd, pin, &src_len, pout, &dst_len) == -1)return -1;iconv_close(cd);*pout = '\0';return 0;
}#endifint main(void)
{char *src_str = "葡萄美酒夜光杯";cout << "origin string: " << src_str << endl;#ifdef _WIN32// windows default is gbkstring dst_str = GbkToUtf8(src_str);cout << "gbk to utf8: " << dst_str << endl;string str_utf8 = Utf8ToGbk(dst_str.c_str());cout << "utf8 to gbk: " << str_utf8 << endl;
#else// unix default is utf8char dst_gbk[1024] = {0};Utf8ToGbk(src_str, strlen(src_str), dst_gbk, sizeof(dst_gbk));cout << "utf8 to gbk: " << dst_gbk << endl;char dst_utf8[1024] = {0};GbkToUtf8(dst_gbk, strlen(dst_gbk), dst_utf8, sizeof(dst_utf8));cout << "gbk to utf8: " << dst_utf8 << endl;
#endifreturn 0;
}