在进行Windows编程时，常常遇到不同字符编码之间的转换以对应不同的输出格式，本文介绍宽字节UTF-8编码格式和多字节之间的项目转换。分别调用Windows底层函数MultiByteToWideChar和 WideCharToMultiByte实现。
1.UTF-8转多字节
std::string u82mb(const char* cont) { if (NULL == cont) { return ""; } int num = MultiByteToWideChar(CP_UTF8, NULL, cont, -1, NULL, NULL); if (num <= 0) { return ""; } wchar_t* buffw = new (std::nothrow) wchar_t[num]; if (NULL == buffw) { return ""; } MultiByteToWideChar(CP_UTF8, NULL, cont, -1, buffw, num); int len = WideCharToMultiByte(CP_ACP, 0, buffw, num - 1, NULL, NULL, NULL, NULL); if (len <= 0) { delete[] buffw; return ""; } char* lpsz = new (std::nothrow) char[len + 1]; if (NULL == lpsz) { delete[] buffw; return ""; } WideCharToMultiByte(CP_ACP, 0, buffw, num - 1, lpsz, len, NULL, NULL); lpsz[len]=‘\0‘; delete[] buffw; std::string rtn(lpsz); delete[] lpsz; return rtn; }
2.多字节转UTF-8
std::string mb2u8(const char* cont) { if (NULL == cont) { return ""; } int num = MultiByteToWideChar(CP_ACP, NULL, cont, -1, NULL, NULL); if (num <= 0) { return ""; } wchar_t* buffw = new (std::nothrow) wchar_t[num]; if (NULL == buffw) { return ""; } MultiByteToWideChar(CP_ACP, NULL, cont, -1, buffw, num); int len = WideCharToMultiByte(CP_UTF8, 0, buffw, num - 1, NULL, NULL, NULL, NULL); if (len <= 0) { delete[] buffw; return ""; } char* lpsz = new (std::nothrow) char[len + 1]; if (NULL == lpsz) { delete[] buffw; return ""; } WideCharToMultiByte(CP_UTF8, 0, buffw, num - 1, lpsz, len, NULL, NULL); lpsz[len]=‘\0‘; delete[] buffw; std::string rtn(lpsz); delete[] lpsz; return rtn ; }
原文：https://www.cnblogs.com/wanlu/p/9542839.html