JAVA高级面试进阶训练营视频教程

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我参考的是这篇文章：https://www.2cto.com/database/201411/354891.html

 

理论是：sqlite使用的是UTF-8，C++中用的字符串是ascii或unicode编码。

         所以使用时候要进行转化。插入中文时候要转化为UTF-8，读取时候再转化回来。

 

下面是转化函数，参考文章：https://www.2cto.com/database/201411/354891.html

    //UTF-8转Unicode 
    std::wstring Utf82Unicode(const std::string& utf8string) {
        int widesize = ::MultiByteToWideChar(CP_UTF8, 0, utf8string.c_str(), -1, NULL, 0);
        if (widesize == ERROR_NO_UNICODE_TRANSLATION)
        {
            throw std::exception("Invalid UTF-8 sequence.");
        }
        if (widesize == 0)
        {
            throw std::exception("Error in conversion.");
        }
        std::vector<wchar_t> resultstring(widesize);
        int convresult = ::MultiByteToWideChar(CP_UTF8, 0, utf8string.c_str(), -1, &resultstring[0], widesize);
        if (convresult != widesize)
        {
            throw std::exception("La falla!");
        }
        return std::wstring(&resultstring[0]);
    }


    //unicode 转为 ascii 
    std::string WideByte2Acsi(std::wstring& wstrcode){
        int asciisize = ::WideCharToMultiByte(CP_OEMCP, 0, wstrcode.c_str(), -1, NULL, 0, NULL, NULL);
        if (asciisize == ERROR_NO_UNICODE_TRANSLATION)
        {
            throw std::exception("Invalid UTF-8 sequence.");
        }
        if (asciisize == 0)
        {
            throw std::exception("Error in conversion.");
        }
        std::vector<char> resultstring(asciisize);
        int convresult = ::WideCharToMultiByte(CP_OEMCP, 0, wstrcode.c_str(), -1, &resultstring[0], asciisize, NULL, NULL);
        if (convresult != asciisize)
        {
            throw std::exception("La falla!");
        }
        return std::string(&resultstring[0]);
    }



    //utf-8 转 ascii 
    std::string UTF_82ASCII(std::string& strUtf8Code){
        using namespace std;
        string strRet = "";
        //先把 utf8 转为 unicode 
        wstring wstr = Utf82Unicode(strUtf8Code);
        //最后把 unicode 转为 ascii 
        strRet = WideByte2Acsi(wstr);
        return strRet;
    }



    //ascii 转 Unicode 
    std::wstring Acsi2WideByte(std::string& strascii){
        using namespace std;
        int widesize = MultiByteToWideChar(CP_ACP, 0, (char*)strascii.c_str(), -1, NULL, 0);
        if (widesize == ERROR_NO_UNICODE_TRANSLATION)
        {
            throw std::exception("Invalid UTF-8 sequence.");
        }
        if (widesize == 0)
        {
            throw std::exception("Error in conversion.");
        }
        std::vector<wchar_t> resultstring(widesize);
        int convresult = MultiByteToWideChar(CP_ACP, 0, (char*)strascii.c_str(), -1, &resultstring[0], widesize);
        if (convresult != widesize)
        {
            throw std::exception("La falla!");
        }
        return std::wstring(&resultstring[0]);
    }


    //Unicode 转 Utf8 
    std::string Unicode2Utf8(const std::wstring& widestring){
        using namespace std;
        int utf8size = ::WideCharToMultiByte(CP_UTF8, 0, widestring.c_str(), -1, NULL, 0, NULL, NULL);
        if (utf8size == 0)
        {
            throw std::exception("Error in conversion.");
        }
        std::vector<char> resultstring(utf8size);
        int convresult = ::WideCharToMultiByte(CP_UTF8, 0, widestring.c_str(), -1, &resultstring[0], utf8size, NULL, NULL);
        if (convresult != utf8size)
        {
            throw std::exception("La falla!");
        }
        return std::string(&resultstring[0]);
    }


    //ascii 转 Utf8 
    std::string ASCII2UTF_8(std::string& strAsciiCode) {
        using namespace std;
        string strRet("");
        //先把 ascii 转为 unicode 
        wstring wstr = Acsi2WideByte(strAsciiCode);
        //最后把 unicode 转为 utf8 
        strRet = Unicode2Utf8(wstr);
        return strRet;
    }

使用效果立竿见影：

可以看出，之前存进数据库的是乱码

改变之后已经成功将汉字存进去了