Qt 6

Hey, I wanted to check-in on this item; I know it was resolved back in 2021 for this case, but since updating to QT 6.8, even with creating a profile and setting the cache/cookie to save to disk, it doesn't seem to "remember" when logging out and back into KDE. Any insight, or maybe point me in the right direction, would greatly be appreciated.

Okey @J-Hilk , Tried by extending Activity, but it is not helping.

Due to some reason not able to access the activity().

@Parvathy2020 said in Qt 6.8 Duplicate symbol: qInitResources:

But I have installed 6.8.0 LTS version

If 6.8 is a LTS version then also all 6.8.x versions are LTS and you should anyway upgrade to these versions to get all the bug fixes.

I just had this problem, and installing libglvnd-devel solved the problem.

sudo dnf install libglvnd-devel

Thanks it work.

@Christian-Ehrlicher I found it. Thank you!

I've tried it.
QT6.5.3 automatically generates XML files, and manual modifications don't take effect.
In addition, I have tried adding the permission in the.pro file ，by adding "ANDROID_PERMISSIONS += android.permission.CHANGE_WIFI_STATE" or ANDROID_MANIFEST method, but neither of them has been successful.

@Parvathy2020
HI,
I have installed QT multimedia thru "Qt Maintenance Tool" for Qt6.8.0 and now its working fine and error goes away.

@Pl45m4 It is workable. thank you!

I have encountered the same error with a library I'm using (SDL2). I don't know whether it is the same library that is causing the issue, but for SDL2 I need to put up a macro to tell it that main() is being handled elsewhere (by QT):

#include <QApplication> #define SDL_MAIN_HANDLED #include <SDL2/SDL.h>

Hope it helps!

@Vernat

Note: The Qt Charts module is in the maintenance phase. For new projects, consider using the Qt Graphs module. To render 2D charts, QtGraphs uses Qt Quick Shapes, which is a more modern GUI technology compared to the outdated Qt Graphics View Framework used by the Qt Charts module.
( https://doc.qt.io/qt-6/qtcharts-index.html )

You said you don't want to deal with QML, but in the future the backend and how Graphs are rendered will be QML even in C++ use cases.

@Vernat said in Qt Graphs. Building 2d plot using c++ only.:

QValueAxis from the charts is not the same as QValueAxis from the graphs.

What is different?
Make your own axis?!

I hope it will be fixed

I don't think they will revert "improvements" to where it was before in QtChart with GraphicsView backend/rendering.

Hi and welcome to devnet,

Without more details about what you are trying to do, it's impossible to answer.
Are you trying to build that file manually ?
Are you using a project management system ?
If so, is it qmake ? cmake ? Something else ?
If one of the two formers, read the QApplication class documentation. You have at the top the instructions on how to make it available with both these tools.

@Pl45m4 Thank you for your reply. I tried. here is my example code:

Version A

void start_app(void) { int argc = 0; char*argv[] = {nullptr}; QCoreApplication a(argc, argv); a.exec(); } void init_dll() { std::thread th(start_app); h.detach(); }

I use QLibrary to resolve "init_dll" function and run it.This time the main program is not blocked, no crash down occured .But the signal slot did not work, and QTCPSocket cannot be used.

Version B

void start_app(void) { int argc = 0; char*argv[] = {nullptr}; QCoreApplication a(argc, argv); a.exec(); } void init_dll() { start_app(); }

when I call "init_dll" function in DLLs，the main program will be blocked from running, but the QTCPSocket and signal slots function is workable.

How can I modify the DLL code so it doesn't block the main program's execution and still allows using QTcpSocket and other Qt components that depend on the event loop(QCoreApplication)?

Thank you for the information.

Thanks Pl45m4 !

I think it will be more reliable if I directly ask to Qt.

We need to set the Qt6HostInfo_DIR as a cmake parameter like -DQt6HostInfo_DIR=/home/...

Is Qt a balloon? Working with Qt on Android has been a struggle for a year. I downloaded Qt 6.8, and this issue still hasn't been resolved. Can you believe it? It'll be 2025. Qt 6.8 has been released, and we still can't use input on Android? I used to enjoy developing with Qt, but I'm starting to wonder if I learned it for nothing.

I'm using Qt 6.8 and I've created an Android application for testing, which includes a TextField. When I click on the TextField, the keyboard comes over the input, and I can't see what is being typed.

if you want to benefit from an LTS, even with free version of Qt, you have to use the latest minor release available, that is 6.5.6, which brings some bugfixes and security patches.
If you use 6.5.0, you won't benefit those fixes that have been introduced from 6.5.1 to 6.5.6.
And it's the same for any version, not only LTS.

@Christian-Ehrlicher said in Error during build from source （AutoMOC）:

There is no advantage for a non-paying customer to stick at a LTS version at all.

I personnaly prefer using the latest LTS over latest version when I don't need the new features as new features also come along with potential new bugs and security issues.

Use the pre-compiled binaries from the Qt online installer - much easier to use and no problems during compilation.

I agree, self-building is not needed.

@JuFu
I do not believe that a "crash" error when running your program can be anything like or have any relation to a "crash" from a compiler. They are two totally different issues.
I do not believe you cannot obtain a "stack trace" if your program crashes at runtime. Try running it from inside a debugger.