how can I get QT main function argv parameter as unicode encoding format

Question

I am new on QT and I have a problem with encoding. This is my main function

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;

    const char *charArray = "çşüğ";

    QStrıng str1(charArray);
    QString str2(argv[1]);
}

argv[1] value is the same with charArray on the caller exe side. But If I control the str1 and str2 values str1 is looking çşüğ but str2 ıs .!?><. I think it is because of encoding type. How can I fix this problem? Caller exe is c# application.

Looks like a duplicate of ["QApplication in unicode"](http://stackoverflow.com/questions/4072016/qapplication-in-unicode) — Nikita, Sep 07 '16 at 21:27
Using non-ASCII characters in a string literal is not a standard feature, so you can't know for sure what bytes actually end up in `charArray`. — roeland, Sep 07 '16 at 21:59
It doesn't really have anything to do with C# directly, although that bit of information lets us know that this is specific to the Windows platform (though that should have been explicitly specified either in the question or the tags). — Dan Korn, Sep 08 '16 at 17:50

score 4 · Accepted Answer · answered Sep 08 '16 at 12:04

Use QCoreApplication::arguments For example

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    if (argc > 1)
    {
        QString str1 = "çşüğ";
        QString str2 = a.arguments().at(1);
    }
    return a.exec();
}

Note that in Windows environment Unicode refers to UTF-16 standard, you need wide char strings, example const wchar_t *charArray = L"çşüğ"; While in Unix based environment Unicode refers to UTF-8.

Qt is supposed to be cross platform compatible so it tries to hide these differences through QString and other functions.

score 0 · Answer 2 · answered Sep 07 '16 at 21:28

0

Change the first line to:

int wmain(int argc, wchar_t *argv[])

Then call GetCommandLineW.

answered Sep 07 '16 at 21:28

Dan Korn

1,274
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`GetCommandLineW` will return the program arguments as Unicode regardless of whether you use `main` or `wmain` or `WinMain`. – roeland Sep 07 '16 at 21:54
True, I guess I should have said "**OR** call GetCommandLineW." – Dan Korn Sep 07 '16 at 21:59
1

@DanKorn It's not possible to use `wmain` here. [`QApplication`](http://doc.qt.io/qt-5/qapplication.html) class doesn't have constructor with `wchar_t**` parameter. – Nikita Sep 08 '16 at 05:03
1

@Nikita: Those two statements are not causally linked. It's true that QApplication doesn't have a constructor that takes a wchar_t**. But that doesn't mean that you can't use wmain. – Dan Korn Sep 08 '16 at 16:40
@DanKorn `QApplication` is used in context of this question, it's central part of QT application. So it's critical to construct proper `QApplication` instance, but it's not possible with `wchar_t**` parameter. – Nikita Sep 08 '16 at 17:02
Yes, QApplication is a central part of a QT application, but its initialization does not seem to be pertinent to the original question here, which is "how can I get QT main function argv parameter as unicode." If you use wmain, or call GetCommandLineW, then you will indeed get the main function argv parameters as Unicode, which, I submit, answers the question posed. – Dan Korn Sep 08 '16 at 17:48

how can I get QT main function argv parameter as unicode encoding format

2 Answers2