QString 和 TCHAR 的相互转换

参考资料:

http://www.cnblogs.com/fuyanwen/p/3200536.html
http://www.cnblogs.com/wendao/archive/2012/07/27/2612597.html

不能直接用:

QString szqFileName = QString::fromLocal8Bit("data");
const char* szName = szqFileName.toLocal8Bit().constData(); // 返回的 QByteArray 被析构掉了, szName 会指向无效的内存区

正确的做法:

QString szqFileName = QString::fromLocal8Bit("data");
QByteArray ba = szqFileName.toLocal8Bit();
const char* szName = ba.constData();

代码(在我的系统上, Win7 x64. CHS. 第21, 40行如果我用utf8的话就会乱码), 下载DEMO:

注: 关于UNICODE宏的设置

 #include <iostream>

 #include <Windows.h>
 #include <QtCore/QtCore>

 #ifdef UNICODE
 #define FILE_NAME "数据.txt"
 #else
 #define FILE_NAME "data.txt"
 #endif

 int main()
 {
     QString szqFileName = QString::fromLocal8Bit(FILE_NAME);
     qint64 nLen = szqFileName.length();
     //
     // QString to TCHAR*
     //
     LPCTSTR szFileName = NULL;
 #ifdef UNICODE
     szFileName = (wchar_t*)szqFileName.utf16();
 #else
     QByteArray byteArray = szqFileName.toLocal8Bit();
     szFileName = byteArray.constData();
 #endif // UNICODE
     //
     // Create file
     //
     HANDLE hFile = ::CreateFile(szFileName, GENERIC_WRITE, , NULL, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, NULL);
     if (hFile == INVALID_HANDLE_VALUE)
         std::cout << "Cannot create file." << std::endl;
     else
         std::cout << "File created." << std::endl;
     ::CloseHandle(hFile);
     //
     // TCHAR* to QString
     //
     szFileName = TEXT(FILE_NAME);
 #ifdef UNICODE
     szqFileName = QString::fromUtf16((ushort*)szFileName);
 #else
     szqFileName = QString::fromLocal8Bit(szFileName);
 #endif
     QFile file(szqFileName);
     if (!file.remove())
         std::cout << "Cannot remove file." << std::endl;
     else
         std::cout << "File removed." << std::endl;

     return ;
 }