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, 0, 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 0;
}