Start an external program from Qt

Timo_F

Hello everybody,

ich developped a vision app and now I want to start that app by pushing a button on an Qt gui.
More precise the button is on the MainWindow.
I found a lot of hints in the web but they are not working for me.

QProcess * my process = new QProcess();
myprocess-> start("absoulte path", QStreingList() << "Start");
I also used startDetached , but that's also not working.
Does anyboy have an example for me?

Thanks a lot.

Kindy regards,

Timo

luca

Have you tried with the static call:

QProcess::startDetached(......);

Timo_F

Yes, but nothing happens ...

tham

@Timo_F Which platform and Qt version? Any error messages?One of the reasons I could imagine is privilege, if you are doing the task on windows, you need to change the privilege by manifest.

Example of manifest :

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
    <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
        <security>
            <requestedPrivileges>
                <requestedExecutionLevel level="asInvoker" uiAccess="false"/>
            </requestedPrivileges>
        </security>
    </trustInfo>
</assembly>

And call the mt.exe, you can save some trouble by adding following lines in .pro

win32 {
    WINSDK_DIR = C:/Program Files (x86)/Windows Kits/10
    WIN_PWD = $$replace(PWD, /, \\)
    OUT_PWD_WIN = $$replace(OUT_PWD, /, \\)
    message("output : " + $$OUT_PWD_WIN)
    QMAKE_POST_LINK = "$$WINSDK_DIR/bin/x86/mt.exe -manifest $$quote($$WIN_PWD\\$$basename(TARGET).manifest) -outputresource:$$quote($$OUT_PWD_WIN\\${DESTDIR_TARGET};1)"
}

Maybe the app compiled by mingw do not need to go through this kind of troubles

Timo_F

@tham
there are no errors ... it's like death. I'm using Qt 5.8 on Windows10.
Where is the manifest doc?

tham

@Timo_F Embedding Application Manifest and Version Information using QtCreator.

mrjj

@Timo_F said in Start an external program from Qt:

@tham
there are no errors ... it's like death. I'm using Qt 5.8 on Windows10.

So you did hook up
http://doc.qt.io/qt-5/qprocess.html#errorOccurred
and see what it says ?

Timo_F

Thank you all a lot. :-)
Now it works ... shame on me, it was so simple. I copied and paste the path directly from the explorer and that was not working. Replacing the "" by "/" in the path was the solution !!

mrjj

@Timo_F
Oh its a classic
to use

\
in any c/c++ it must be escaped
\\
or use / as Qt supports.