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Qt 6

This is where all Qt 6 related questions belong

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  • Read before posting in this category!

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    SGaistS
    And now (incomplete at the time of this post): https://wiki.qt.io/New_Features_in_Qt_6.2
  • Qt5 is better than Qt6

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    @DevWinDemon said in Qt5 is better than Qt6: Why they can't just create normal compiler that can create apps normally without problems. That is because the easiest way to conform with the LGPL is to use DLLs. What you want is static linking (which is a little harder to adhere to with the LGPL). But, what you probably really want is the paid version of Qt. @DevWinDemon said in Qt5 is better than Qt6: Why they can't just create normal compiler that can create apps normally without problems. On Windows, most libraries work like that. It is quite common to use DLLs. This always has a certain baggage attached to it. The most common way to solve this is to use an installer. I'm not sure where you got the idea that Qt should create a "normal compiler" because they never had a compiler in the first place.
  • How to use QProcess with QtConcurrent?

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    JonBJ
    @Teg-Miles It's not so much that QProcess "wasn't created for threading", it's that there is no need (and only added complexity) to use threads to run the the processes since another process is asynchronous anyway. It won't even use any calling threads you might create anyway, as soon as a sub-process runs it is in its own thread/process anyway, not the one which ran it. No, ps will not be faster than, say, reading from /proc yourself as that is what it will be doing anyway --- it's not magic, it has to be written in C/C++ itself anyway. OTOH there is an overhead inherent in creating and running another process, plus whatever IPC or I/O you do to get its data back. That will be true on Windows too. I assume Get-Process is a PowerShell command a bit like ps? So again that is just one way you could call it. There will also be Windows own system calls to get information about other processes, and calling those yourself from C/C++ will get better performance. But finding out how to do this in Linux/Windows/MacOS may be something you don't want to do and you find running some command on each OS and reading its output is what you prefer for a simple, non-commercial program.
  • Qt 6.8.3 or higher Font displays incorrectly on systems with Japanese language.

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    SGaistS
    You can use qDebug to print your application's font information.
  • Qt Applications Font doesn't look right.

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    @Cruzmatt22 I do have WinAero Tweaker installed but System Font is set to default. Also the command line parameter did work. I was hoping there was some sort global fix.
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    Christian EhrlicherC
    @DevWinDemon said in The code execution cannot proceed because Qt6Core.dll was not found. Reinstalling the program may fix this problem.: I work 2 years like this on qt 5.15.16 Nobody hinders you to make it work the same with Qt6 - simply put it in the PATH env var as you did for Qt5. Please stop insulting people for things neither we nor Qt can do against - that's how a library search path on windows works (and also on linux there is a similar thing). So learn on how library search is working on your platform. But maybe your russia os has a better solution for this...
  • Install Qt6StateMachine with aqt install-qt

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    Thanks @Paul-Colby This was helpful.
  • Qt6 + GStreamer

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    SGaistS
    Are you setting the CMAKE_PREFIX_PATH variable to point to the Qt version you want to use ?
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    @SGaist sure will do that ...
  • How to create exe file on qt6

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    I tried, I ran in release mode and used windeployqt and had to copy additional lib files but it couldn't run and there was no notification, but if I run the program in debug mode, after the exe file is created, I can successfully run that file without having to run the windeployqt command or copy any additional lib files
  • This topic is deleted!

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  • error when building android on qt6.8.3 clang arm64-v8a

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    jsulmJ
    @Xhuong It looks like jpeg lib is not there or incompatible (wrong CPU architecture?).
  • Qt 6 undefined reference to `qMain(int, char**)'

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    QtFriend2024Q
    ** MY SOLUTION ** I had this same issue with my QT Widgets project using Windows 11 host machine. I had upgraded my QT to 6.8.3 and this Error: undefined reference to `qMain(int, char)'** even though this wasn't the actual issue . Following my steps below, Qt Creator was able to highlight the actual issues for me to resolve and successfully build my project. Steps to Resolve the Issue: Create a new, most simple Qt Widgets project. Use the default mainwindow.h, mainwindow.cpp and mainwindow.ui with the project kit that you want to use Run CMake Build the project. It should build successfully Open the CMakeLists.txt file Utilize this new, simple CMakeLists.txt file as a template for your ORIGINAL project. Modify the "template" CMakeLists.txt file to include your original project's resource file names where you see main.cpp, mainwindow.h, mainwindow.cpp, etc. Modify the "template" CMakeLists.txt file to include the QT packages you are using (Core, Gui, or etc.) Modify the "template" CMakeLists.txt file to include the target link libraries (refer to packages in previous step) Build your original project It should give you more specific, helpful errors to resolve (if there are any). For me, one of my *.cpp files #include Qt Serial Bus but I forgot to add it to CMakeLists.txt Resolve errors Rebuild. It built successfully for me.
  • Qt CAN Bus (vectorcan) with Vector VN1640A only receives data when CANoe is running

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    aha_1980A
    Hi @eric_1994, I just stumbled over https://bugreports.qt.io/browse/QTBUG-123012 and wonder if that is related to your problem? Can you update to Qt 6.9?
  • setSpan() functionality not working in qt 6 and cpp 17

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    Christian EhrlicherC
    Please provide a minimal, compilable example of your problem.
  • How to determine system encoding in Qt 6?

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    Thanks a lot!
  • There has a the difference about QTransform between qt5 and qt6, How can I do?

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    Christian EhrlicherC
    @JohanSolo said in There has a the difference about QTransform between qt5 and qt6, How can I do?: if and only if its determinant is different from zero, Yeah, forgot the not, thx & fixed
  • Example code for applying for Android permissions in QT 6.5.3.

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    @Gracy The question is pretty old, but i know the answer... First, make sure, the permissions are added. Maybe you are missing the following: https://doc.qt.io/qtcreator/creator-deploying-android.html#editing-manifest-files To check and request permissions you can do: QFuture permission_request = QtAndroidPrivate::requestPermission("android.permission.WRITE_EXTERNAL_STORAGE"); switch(permission_request.result()) { case QtAndroidPrivate::Undetermined: qWarning() << "Permission for writing to the storage undetermined!"; break; case QtAndroidPrivate::Authorized: qDebug() << "Permission for writing to the storage authorized"; break; case QtAndroidPrivate::Denied: qWarning() << "Permission for writing to the storage denied!"; break; }
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    Could not find a package configuration file provided by "Qt6HostInfo" with any of the following names:
  • Build error on qt 6.8

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    @Axel-Spoerl said in Build error on qt 6.8: gcc --version it say: gcc (GCC) 13.2.1 20240316 (Red Hat 13.2.1-7) Copyright (C) 2023 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.