Sqlite中文亂碼問題

sqlite數據庫使用的是UTF-8編碼方式。而c++用的通常是ASCII編碼或Unicode編碼方式。因此插入，查詢時經常會出現亂碼。

1.UTF-8轉Unicode

std::wstring Utf8ToUnicode(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]); 
}

2.unicode 轉爲 ascii 

string WideByte2Acsi(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]); 
}

3.utf-8 轉 ascii 

string UTF_82ASCII(string& strUtf8Code) 
{ 
string strRet(""); 
//先把 utf8 轉爲 unicode 
wstring wstr = Utf82Unicode(strUtf8Code); 
//最後把 unicode 轉爲 ascii 
strRet = WideByte2Acsi(wstr); 
return strRet; 
}

4.ascii 轉 Unicode 

wstring Acsi2WideByte(string& strascii) 
{ 
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]); 
}

5.Unicode 轉 Utf8

std::string Unicode2Utf8(const std::wstring& widestring) 
{ 
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]); 
}

6.ascii 轉 Utf8 

string ASCII2UTF_8(string& strAsciiCode) 
{ 
string strRet(""); 
//先把 ascii 轉爲 unicode 
wstring wstr = Acsi2WideByte(strAsciiCode); 
//最後把 unicode 轉爲 utf8 
strRet = Unicode2Utf8(wstr); 
return strRet; 
}