I tried to create a C++ project with Qt I stumbled across different kinds of guides which all refer to a special '.pro' file inside the project where I have to adjust a setting so the SQL part takes effect.
My problem: whenever I create a new project - doesn't matter whether its with qbs, qmake, or cmake - the project structure/ folder is lacking the '.pro' file.
Currently I'm using Qt 5.15.2 (via QT Creator) with MinGW Kit and cmake/ qbs.
As I'd like to play around with SQL-based apps.
Maybe I'm just skipping/ overlook something?
TL;DR: Use cmake. Forget about qbs and qmake.
Whenever I create a new project - doesn't matter whether its with qbs, qmake, or cmake - the project structure/ folder is lacking the '.pro' file.
A qmake project will have the .pro file, since that's the project file for qmake. Maybe you're looking in a wrong place? A qbs project will have a .qbs file, since that's what qbs uses. A cmake project will have CMakeLists.txt, since that's what cmake uses. It all works for me.
I'm just confused by all these guides stating that I have to add QT += widgets sql in the .pro file.
Those guides only apply when you use qmake, since .pro are qmake project files.
I suggest that you use cmake, as qbs is abandoned now, and there's no benefit to using Qt-specific qmake over the widely supported and continuously developed cmake.
Qt documentation covers the basics of how to use cmake to build Qt projects.
Qt support is provided natively by cmake, and it thus provides a comprehensive reference page.
Related
I want to connect Qt with Sqlite. Everyone on YouTube says that we need to type QT += core gui sql inside of .pro file, but the problem is that after I created a Qt Widget Application I haven't found the .pro file. Probably the problem is connected with using CMake, but I cannot change to qmake, because our lecturer told us to use CMake in our coursework. I wish the problem is not that hard, and beautiful community is able to help me.
Since you created a CMake-based project, the corresponding project file is called CMakeLists.txt, not a .pro file.
The corresponding command to QT += sql for linking against the Qt Sql module, is find_package(Qt5 COMPONENTS Sql REQUIRED) for CMake projects.
See also the Get Started with CMake documentation from the Qt documentation.
I've read through the tutorials of Qt, I've searched the net, but I can't find the exact way on how to build custom witgets with Qt 5.8.x. In example with this tutorial one is able to build widgets for Qt 4.x as I already succeeded. For Qt 5.8.x I'am lacking in such straightforward tutorials.
Even if you use the build in wizard of Qt for setting up such custom widgets projects, one will end up with none recognized widget libraries.
So first of all, there is a confusion with the installing path, that the makefile should mention while installing the plugin.
In the project file one can find the section
target.path = $$[QT_INSTALL_PLUGINS]/designer
INSTALLS += target
After a straightforward installation of the open source mingw version of Qt 5.8.0 on a windows 7 machine in the path C:\Qt\Qt5.8.0, the variable "QT_INSTALL_PLUGINS" will extend to
C:\Qt\Qt5.8.0\5.8\mingw53_32\plugins
thus the "target.path" for the
make install
will be read as
C:\Qt\Qt5.8.0\5.8\mingw53_32\plugins\designer
But on the plain installation of Qt 5.8.0 with mingw the designer searches its plugins in
C:\Qt\Qt5.8.0\Tools\QtCreator\bin\plugins\designer\
As someone already suggested to me, one has to set the environment variable "QT_PLUGIN_PATH", where Qt Creator as well as Qt Designer ( in the subdirector "designer") searches its plugins in. So in order that Qt Creator still works properly one has to set the environment variable "QT_PLUGIN_PATH" to
the original path as well as to
the install path reffered to by $$[QT_INSTALL_PLUGINS]
So on my Windows 7 environment I set the variable "QT_PLUGIN_PATH" to
C:\Qt\Qt5.8.0\Tools\QtCreator\bin\plugins;C:\Qt\Qt5.8.0\5.8\mingw53_32\plugins
Afterwards Qt Designer is able to find the custom build widget library. But Qt Designer it not able to load the library. One interesting thing is that the designer also refuses the libraries provided by the installation of Qt itself.
on loading the custom widget lib it says:
"... .dll can't be loaded: the given procedure was not found"
on loading the libs supplied by the Qt distribution itselfs in the path C:\Qt\Qt5.8.0\5.8\mingw53_32\plugins\designer it says:
"... .dll cant be loaded: the mentioned modul was not found"
What I've done to build the library is, that I just ran through the project wizard to generate a custom widget for Qt Designer. With the so generated project I get the result of a non loadable lib, as mentioned above.
What do I have to change in the source/project files in order that the Qt Designer ist able to load the lib properly?
Thanks for any hints or suggestions!
You seem to use the MinGW compiler.
You cannot make plugins with that compiler with the default supplied Creator as it's compiled with Visual Studio 2013/2015 (depending on the Qt version).
Due to how DLLs works on Windows, you must use the same compiler that Creator is compiled with to build the plugin (otherwise it can't load it).
Go to "About Qt Creator" in the Help menu to check.
Also make sure to build the plugin in Release mode.
I am trying to import a generic project into Qt creator by following this tutorial.
The project has its Makefile which builds multiple separate executables.
Running make all in the root directory of the project builds everything correctly.
The project has been imported into Qt creator and the sources show no errors regarding includes. When I press build, i get the error No rule to make targetall'. Stop.` As if the Makefile is non existent.
Where is Qt creator looking for the Makefile?
In my case the problem was with the custom build directory in the Build Settings.
Qt creator was searching for the Makefile in the build directory.
When using Qt creatror for Qt projects, I've usually set the build directory to something custom but this isn't sensible here :)
Does it make sense to add relevant Qt Libs and headers (opensource version) to a projects repository or should I just reference them from the sdk directory ?
I (alone) am developing a cross-platform (windows/linux) c++ application which, will be using a number of thirdparty opensource libraries including Qt, OpenCV, log4cpp to name a few.
I started off development in Qt Creator for convenience (speedy GUI creation). Currently I have the Qt Sdk installed on both Linux and Windows outside the project directory.
I'm planning to move to CMAKE to for better configurability, e.g out-of-source builds and independance from Qt Creator and I would like to have all dependencies included in the project directory structure -so that I or anyone else can checkout the project and build without needing to install any other dependancies.
I have added all libs but Qt's to the directory as I am a little unsure weather its worth it -it seems like CMAKE depends on the Qt Sdk for compiling Qt specific files i.e moc, ui etc... (see here) is this the case ? or is there a better suited build tool ? (Originally I was I going to use Scons but I decided not to as the there seemed to be limited support.. and there hasn't been developement on Qt4 Tools since 2010, which doesnt inspire confidence either.)
Qt is too big to be put in a project directory, even if you include only one of its modules. Also you have some convenient functions in CMake to use Qt (add moc, rcc, ui). You can even write these functions by yourself (in fast, they just add a pre-build command).
For the build operations: you will need to use the moc (and maybe ui, rcc, ...), which is not provided by CMake. So, a person wanting to build your application must have the Qt SDK installed. Luckily, this installation is very easy.
I've heard that it is possible to build non-Qt applications (like simple C++ HelloWorld) with Qt Creator. I downloaded and installed Qt Creator, and tried to compile simple code with it. But I didn't succeed: Creator needs qmake to create makefile.
Although the package I downloaded includes MinGW, there is no qmake inside of it.
I still want to use it just like an IDE to create simple C++ sources and compile them with MinGW. Is it possible to use Qt Creator without installing whole platform?
Qt Creator support CMake projects, you just need to choose Open a file or project and select the root CMakeList.txt of your project.
If you want to define your own build workflow, you can remove the default build step and create your own custom build steps (Qt Creator Build Steps).
I think you can modify the build step to remove qmake and use your custom make file.
You totally can!
You can write a .pro file yourself and use it as a project file to use QtCreator without linking / using any of the Qt libraries.
In Project / Compilation Parameters, you can actually tune the compilation steps (removing the qmake step and adding your own).
I use it for a big project of mine and it's very efficient: QtCreator's C analyzer is diamond.
Here's a sample project file for me:
TEMPLATE = app
TARGET =
DEPENDPATH += . include
INCLUDEPATH += . include
# Input
HEADERS += include/x.h \
include/y.h \
include/z.h
SOURCES += src/x.cpp
Note that I actually use qmake to generate this file automatically, but you can also put your hands into it and modify it by hand.
Afterwards, it's only a matter of $ qtcreator yourfile.pro.