编码转换 UTF-8、GB2312、Unicode、ANSI

UTF-8 转 GB2312

#include <windows.h>
#include <string>
#include <vector>

std::string Utf8ToGb2312(const std::string& utf8) {
    int len = MultiByteToWideChar(CP_UTF8, 0, utf8.c_str(), -1, nullptr, 0);
    std::vector<wchar_t> wideCharStr(len);
    MultiByteToWideChar(CP_UTF8, 0, utf8.c_str(), -1, &wideCharStr[0], len);

    len = WideCharToMultiByte(936, 0, &wideCharStr[0], -1, nullptr, 0, nullptr, nullptr);
    std::vector<char> gb2312Str(len);
    WideCharToMultiByte(936, 0, &wideCharStr[0], -1, &gb2312Str[0], len, nullptr, nullptr);

    return std::string(gb2312Str.begin(), gb2312Str.end() - 1);
}

GB2312 转 UTF-8

std::string Gb2312ToUtf8(const std::string& gb2312) {
    int len = MultiByteToWideChar(936, 0, gb2312.c_str(), -1, nullptr, 0);
    std::vector<wchar_t> wideCharStr(len);
    MultiByteToWideChar(936, 0, gb2312.c_str(), -1, &wideCharStr[0], len);

    len = WideCharToMultiByte(CP_UTF8, 0, &wideCharStr[0], -1, nullptr, 0, nullptr, nullptr);
    std::vector<char> utf8Str(len);
    WideCharToMultiByte(CP_UTF8, 0, &wideCharStr[0], -1, &utf8Str[0], len, nullptr, nullptr);

    return std::string(utf8Str.begin(), utf8Str.end() - 1);
}

Unicode 转 ANSI

std::string UnicodeToANSI(const std::wstring& unicodeStr) {
    int len = WideCharToMultiByte(CP_ACP, 0, unicodeStr.c_str(), -1, nullptr, 0, nullptr, nullptr);
    std::vector<char> ansiStr(len);
    WideCharToMultiByte(CP_ACP, 0, unicodeStr.c_str(), -1, &ansiStr[0], len, nullptr, nullptr);
    return std::string(ansiStr.begin(), ansiStr.end() - 1);
}

ANSI 转 Unicode

std::wstring ANSIToUnicode(const std::string& ansiStr) {
    int len = MultiByteToWideChar(CP_ACP, 0, ansiStr.c_str(), -1, nullptr, 0);
    std::vector<wchar_t> unicodeStr(len);
    MultiByteToWideChar(CP_ACP, 0, ansiStr.c_str(), -1, &unicodeStr[0], len);
    return std::wstring(unicodeStr.begin(), unicodeStr.end() - 1);
}