调用Windows API实现GBK和UTF-8的相互转换

GBK转UTF-8示例

GbkToUtf8.cpp

#include <Windows.h>
#include <iostream>
#include <string>
#include <fstream>
int main()
{
    using namespace std;
    string multiByteString = "我25岁。
I'm 25 years old.";
    int bufferSize = MultiByteToWideChar(CP_ACP, 0, multiByteString.c_str(), -1, nullptr, 0);
    WCHAR *unicodeString = new WCHAR[bufferSize];
    MultiByteToWideChar(CP_ACP, 0, multiByteString.c_str(), -1, unicodeString, bufferSize);
    bufferSize = WideCharToMultiByte(CP_UTF8, 0, unicodeString, -1, nullptr, 0, nullptr, nullptr);
    CHAR *utf8String = new CHAR[bufferSize];
    WideCharToMultiByte(CP_UTF8, 0, unicodeString, -1, utf8String, bufferSize, nullptr, nullptr);
    ofstream ofs("UTF8.txt");
    if (ofs)
    {
        ofs.write(utf8String, bufferSize - 1);
        cout << "A UTF-8 string has been written to file: UTF8.txt" << endl;
    }
    else
    {
        cout << "Cannot create file: UTF8.txt" << endl;
    }
    delete[] utf8String;
    delete[] unicodeString;
    system("pause");
    return 0;
}

UTF-8转GBK示例

Utf8ToGbk.c

#include <Windows.h>
#include <stdio.h>
#define BUFFER_SIZE 1000
int main()
{
    const char *inputFilename = "Utf8Text.txt";
    FILE *inputFile = fopen(inputFilename, "r");
    if (inputFile)
    {
        char utf8Text[BUFFER_SIZE];
        size_t numberOfObjectsRead = fread(utf8Text, sizeof(char), BUFFER_SIZE, inputFile);
        utf8Text[numberOfObjectsRead] = '';
        int bufferSize = MultiByteToWideChar(CP_UTF8, 0, utf8Text, -1, NULL, 0);
        WCHAR *unicodeString = (WCHAR *)malloc(sizeof(WCHAR) * bufferSize);
        MultiByteToWideChar(CP_UTF8, 0, utf8Text, -1, unicodeString, bufferSize);
        bufferSize = WideCharToMultiByte(CP_ACP, 0, unicodeString, -1, NULL, 0, NULL, NULL);
        CHAR *gbkString = (CHAR *)malloc(sizeof(CHAR) * bufferSize);
        WideCharToMultiByte(CP_ACP, 0, unicodeString, -1, gbkString, bufferSize, NULL, NULL);
        const char *outputFilename = "GbkText.txt";
        FILE *outputFile = fopen(outputFilename, "w");
        if (outputFile)
        {
            fwrite(gbkString, sizeof(CHAR), bufferSize - 1, outputFile);
            fclose(outputFile);
            printf("The GBK text has been written to file: %s
", outputFilename);
        }
        else
        {
            printf("Cannot write file: %s
", outputFilename);
        }
        free(gbkString);
        free(unicodeString);
        fclose(inputFile);
    }
    else
    {
        printf("Cannot read file: %s
", inputFilename);
    }
    system("pause");
    return 0;
}

以下是我对转换过程的封装

EncodingConverter.h

#pragma once
#include <Windows.h>
#include <string>
class EncodingConverter
{
public:
    EncodingConverter(UINT fromCodePage, UINT toCodePage);
    std::string convert(const std::string &from) const;
    static std::wstring convertToUnicode(UINT fromCodePage, const std::string &from);
    static std::string unicodeConvertTo(UINT toCodePage, const std::wstring &from);
private:
    UINT fromCodePage;
    UINT toCodePage;
};

EncodingConverter.cpp

#include "EncodingConverter.h"
EncodingConverter::EncodingConverter(UINT fromCodePage, UINT toCodePage) : fromCodePage(fromCodePage), toCodePage(toCodePage) { }
std::string EncodingConverter::convert(const std::string &from) const
{
    int bufferSize = MultiByteToWideChar(fromCodePage, 0, from.c_str(), -1, nullptr, 0);
    WCHAR *unicodeString = new WCHAR[bufferSize];
    MultiByteToWideChar(fromCodePage, 0, from.c_str(), -1, unicodeString, bufferSize);
    bufferSize = WideCharToMultiByte(toCodePage, 0, unicodeString, -1, nullptr, 0, nullptr, nullptr);
    CHAR *to = new CHAR[bufferSize];
    WideCharToMultiByte(toCodePage, 0, unicodeString, -1, to, bufferSize, nullptr, nullptr);
    std::string toString(to);
    delete[] to;
    delete[] unicodeString;
    return toString;
}
std::wstring EncodingConverter::convertToUnicode(UINT fromCodePage, const std::string &from)
{
    int bufferSize = MultiByteToWideChar(fromCodePage, 0, from.c_str(), -1, nullptr, 0);
    WCHAR *unicodeString = new WCHAR[bufferSize];
    MultiByteToWideChar(fromCodePage, 0, from.c_str(), -1, unicodeString, bufferSize);
    std::wstring toString(unicodeString);
    delete[] unicodeString;
    return toString;
}
std::string EncodingConverter::unicodeConvertTo(UINT toCodePage, const std::wstring &from)
{
    int bufferSize = WideCharToMultiByte(toCodePage, 0, from.c_str(), -1, nullptr, 0, nullptr, nullptr);
    CHAR *to = new CHAR[bufferSize];
    WideCharToMultiByte(toCodePage, 0, from.c_str(), -1, to, bufferSize, nullptr, nullptr);
    std::string toString(to);
    delete[] to;
    return toString;
}

EncodingConversionDemo.cpp

#include <iostream>
#include "EncodingConverter.h"
using namespace std;
int main()
{
    const string &utf8String = EncodingConverter(CP_ACP, CP_UTF8).convert("Are you OK? -- 你还好吗");
    cout << utf8String << endl;
    const string &gbkString = EncodingConverter(CP_UTF8, CP_ACP).convert("浣犺繕濂藉悧");
    cout << gbkString << endl;
    const wstring &unicodeString = EncodingConverter::convertToUnicode(CP_UTF8, "浣犺繕濂藉悧");
    wcout.imbue(locale("chs"));
    wcout << unicodeString << endl;
    cout << EncodingConverter::unicodeConvertTo(CP_ACP, wstring(L"别笑青蛙没有见过大海，在河边一样可以自由自在。")) << endl;
    system("pause");
    return 0;
}