UE4 字符编码

UE4 字符编码

在UE4中的所有字符串，都作为FString或TCHAR数组以UTF-16存储在内存中，即UE4中的字符串是以“等宽字节”组成的。

UE4 字符编码转换

 /**
 *	Usage:
 *
 *		SomeApi(TCHAR_TO_ANSI(SomeUnicodeString));
 *
 *		const char* SomePointer = TCHAR_TO_ANSI(SomeUnicodeString); <--- Bad!!!
 */
// Usage of these should be replaced with StringCasts.
#define TCHAR_TO_ANSI(str) (ANSICHAR*)StringCast<ANSICHAR>(static_cast<const TCHAR*>(str)).Get()
#define ANSI_TO_TCHAR(str) (TCHAR*)StringCast<TCHAR>(static_cast<const ANSICHAR*>(str)).Get()
#define TCHAR_TO_UTF8(str) (ANSICHAR*)FTCHARToUTF8((const TCHAR*)str).Get()
#define UTF8_TO_TCHAR(str) (TCHAR*)FUTF8ToTCHAR((const ANSICHAR*)str).Get()

其他

TCHAR_TO_UTF8

Windows平台上实现String2UTF8

 std::string String2UTF8(const std::string& str)
    {
        int nwLen = ::MultiByteToWideChar(CP_ACP, 0, str.c_str(), -1, NULL, 0);

        wchar_t* pwBuf = new wchar_t[nwLen + 1];
        ZeroMemory(pwBuf, nwLen * 2 + 2);

        ::MultiByteToWideChar(CP_ACP, 0, str.c_str(), str.length(), pwBuf, nwLen);

        int nLen = ::WideCharToMultiByte(CP_UTF8, 0, pwBuf, -1, NULL, NULL, NULL, NULL);

        char* pBuf = new char[nLen + 1];
        ZeroMemory(pBuf, nLen + 1);

        ::WideCharToMultiByte(CP_UTF8, 0, pwBuf, nwLen, pBuf, nLen, NULL, NULL);

        std::string retStr(pBuf);

        delete[]pwBuf;
        delete[]pBuf;

        pwBuf = NULL;
        pBuf = NULL;

        return retStr;
    }
   

UTF8_TO_TCHAR

Windows平台上实现UTF82String

 std::string UTF82String(const std::string& str)
    {
        int nwLen = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), -1, NULL, 0);

        wchar_t* pwBuf = new wchar_t[nwLen + 1];//
        memset(pwBuf, 0, nwLen * 2 + 2);

        MultiByteToWideChar(CP_UTF8, 0, str.c_str(), str.length(), pwBuf, nwLen);

        int nLen = WideCharToMultiByte(CP_ACP, 0, pwBuf, -1, NULL, NULL, NULL, NULL);

        char* pBuf = new char[nLen + 1];
        memset(pBuf, 0, nLen + 1);

        WideCharToMultiByte(CP_ACP, 0, pwBuf, nwLen, pBuf, nLen, NULL, NULL);

        std::string retStr = pBuf;

        delete[]pBuf;
        delete[]pwBuf;

        pBuf = NULL;
        pwBuf = NULL;

        return retStr;
    }

注意

Visual Studio 编辑器默认编码为“等宽字节”编码，非UTF8；Sqlite3 API默认的编码为UTF8。编辑器编码与接口API字符编码往往会不一致。

参考

1. UE4 字符编码