I am building an application using Qt C++ and I want it to run on windows computers without having to install VC Redistributables. Apparently when user tries to run the application an error pops that says that VCRUNTIME140.dll is missing.
Build both Qt and your application using compiler option /MT?
https://learn.microsoft.com/en-us/cpp/build/reference/md-mt-ld-use-run-time-library?view=msvc-170
I recommend using GCC (i.e. MinGW) as the compiler. If you do that, your app will generall depend on the msvcrt.dll that comes with Windows and doesn't need to be installed specially (but it depends on exactly how the GCC compiler is configured). It will also possibly depend on some GCC runtime library DLLs that you can just put in the same directory as your EXE.
MSYS2 is a good development environment for using MinGW on Windows: https://msys2.org
I also made a useful set of tools that is capable of cross-compiling statically-linked MinGW/Qt applications from Linux: https://github.com/DavidEGrayson/nixcrpkgs
The Qt applications I build with nixcrpkgs come out as single, standalone EXEs that do not need to be shipped with any DLLs.
I'm trying to compile and run an application on a MacBook using Qt Creator. There are no issues compiling the project, but when I try and run it, it seems to be unable to load a plugin.
Could not load the Qt platform plugin "cocoa" in "" even though it was found.
The application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
This error occurs both when trying to run the application from Qt Creator or via Finder. It seems to only happen when I use the CMake build system (no issues when using QMake), but my existing project that I need to deploy on MacOS uses CMake.
My steps to reproduce are:
Install a completely clean MacOS (no user data)
Install Xcode 11
Install CMake 3.15
Install Qt 5.13.1 MacOS package
Open QtCreator->New Project->Qt Quick Application - Scroll
Set build system to CMake (important)
Compile and notice error
I am using:
Qt 5.13.1
macOS Catalina 10.15
Apple Clang 11
I recognize that for final user deployment I will need to use the macqtdeploy tool to copy the Qt libraries to the executable folder, but I should be able to run my app from QtCreator without doing this? Especially as it works fine when using QMake.
So it ended up being some kind of name resolution thing where Qt Creator couldn't decide whether to use the debug or release versions of the framework. Supplying DYLD_IMAGE_SUFFIX=_debug fixed this (add this to the environment section under Kits).
Because I am not a Java enthusiast, I decided to use C++ and Qt for one of my projects. However, I came across the big cross-compiling Qt problem, and I am unable to produce an .exe file for Windows users.
My setup
Linux Ubuntu 12.04, with Wine and Qt. qmake -v gives the following output :
QMake version 2.01a
Using Qt version 4.8.1 in /usr/lib/x86_64-linux-gnu
I also have a MinGW32 compiler, which can be found at /usr/bin/i586-mingw32msvc-g++. My Wine drive_c folder contains the following Qt directories :
$HOME/.wine/drive_c/Qt/Qt5.2.0/5.2.0/Src
$HOME/.wine/drive_c/Qt/Qt5.2.0/5.2.0/mingw48_32
The mingw48_32 directory contains the necessary include/ and lib/ directories, which are used in my mkspec file, /usr/share/qt4/mkspecs/win32-x-g++/qmake.conf :
QMAKE_INCDIR_QT = /home/me/.wine/drive_c/Qt/Qt5.2.0/5.2.0/mingw48_32/include
QMAKE_LIBDIR_QT = /home/me/.wine/drive_c/Qt/Qt5.2.0/5.2.0/mingw48_32/lib
The problem
According to most guides I've found about Qt cross-compiling, my setup should be enough to run a simple :
qmake -spec win32-x-g++
make
wine /path/to/my/application.exe
But... nothing's linked. QApplication and every other symbol I use in my program are "not found". No QApplication, no QPushButton, no connect(), no SIGNAL(), no SLOT()...
My objective here is to successfully configure QtCreator to use this setup (in an independent build configuration), so that it can build a Linux executable (through the first and working configuration), and a Win32 .exe (through the MinGW setup above). However, I cannot modify a single build step in QtCreator :
Cannot add a "MinGW" toolchain : it is not available in the "Add" dropdown list.
Cannot change the -spec parameter value in the project build configurations panel. The field is non-editable.
Despite guides and solutions I found all over the Internet, my only solution so far is to send my source code to a virtual Windows machine, and have it create a new project with it. On this VM, I could probably compile for Windows... But of course, this doesn't actually sound like a real "solution" to me...
Is there any way Qt(Creator) has finally made cross-compiling easier now ? I'm getting a bit tired of "symbol not found" errors...
First,
sudo apt-get install mingw-w64
Then, check if Qt Creator finds the toolchain.
Next, until Ubuntu starts providing a mingw-w64-qt package, download the Qt source and build it. This is bound to get messy, and maybe even the simplest thing to do is to install WINE and use a Windows Qt version.
I would like to create a gui application with Qt, using opencv on Windows XP. I used both Qt and opencv before, but never together. Long story short, I'm unable to get opencv work with Qt.
As on all the forums I searched there are just little pieces of information scattered around, usually with no answer, I summarize here all the steps I've taken.
Downloaded the Qt SDK (4.6.3) for Windows, and used it for some time, successfully.
Downloaded the opencv 2.3.1 megapack for Windows, complete with binaries. I managed to compile my Qt project including opencv successfully, but any opencv function call resulted in a crash. I read on some forums that the binaries in the Windows megapack don't support Qt, and I have to build opencv myself
I downloaded the latest version of CMake (2.8).
I downloaded the source of opencv from here: http://code.opencv.org/svn/opencv/branches/2.3/
I downloaded the source for the version of Qt I had (4.6.3)
I found my old version of visual Studio 2005
I created a VS2005 project with CMake, checking the support for Qt. (WITH_QT checked)
I built opencv in VS2005. It created most of the libraries, but not all. Highgui was among the failed ones. The problem: Qt\4.6.3\src\corelib\global\qconfig.h was not found. There was no qconfig.h at all in the source I downloaded! I found some templates qconfig-large.h, qconfig-small.h etc., so I renamed one of them to qconfig.h. Now I got a screen full of linker errors.
I downloaded the latest Qt source instead (4.8.1). Now there is a source file qbenchmark.h that includes QtTest/qbenchmarkmetric.h which cannot be found.
I gave up, and tried MinGW.
I downloaded the latest MinGW (2011.11.18)
I set CMake to generate a MinGW makefile, but I got the following error:
.
CMake Error at C:/Program Files/CMake 2.8/share/cmake-2.8/Modules/Platform/Windows-g++.cmake:1 (INCLUDE):
include could not find load file:
C:/Program Files/CMake 2.8/share/cmake-2.8/Modules/Platform/Windows-gcc.cmake
Call Stack (most recent call first):
C:/Program Files/CMake 2.8/share/cmake-2.8/Modules/CMakeCXXInformation.cmake:59 (INCLUDE)
True, there is a Windows-g++.cmake file in the Modules/Platform directory, but it references Windows-gcc.cmake which does not exist!
Is there anyone who managed to build opencv with Qt support on Windows, and if yes, how?
Edit:
The problem is definitely with the Qt source. I managed to generate a MinGW makefile, and the build went all OK until it stopped in src/testlib/qtestsystem.h because there was an include for QtCore/qelapsedtimer.h which file is in a completely different directory! Does Qt release incomplete sources, or did I do something wrong?
Edit2
My torment continues. I cleaned everything and started anew. This time without even trying Visual Studio.
I downloaded the latest Qt libs with source (4.8.1)
I downloaded the latest MinGW (2011.11.18)
With CMake I successfully created a Makefile, and built it with MinGW. I got some shiny new libs (libopencv_core231, etv.). I was very happy, but how wrong I was to celebrate that soon!!
I downloaded the latest Qt SDK (strangely, it was 4.8.0, so I set Qt Creator to use the 4.8.1) and created a test program without opencv to see if it works. It worked!
I tried using opencv, just reading and displaying an image. It didn't work. exited with code -1073741511
I tried running the .exe directly, outside of Qt Creator. It complained of a missing libstdc++-6.dll
I did a search for it, and found on in my MinGW install (c:\mingw\bin, 958 KB), and one in my Qt install (c:\qt\mingw\bin, 793 KB) - this mingw came bundled with Qt.
I tried both, by copying them in the same folder where my .exe is, but neither worked. I got "The procedure entry point _ZNSt9exceptionD2Ev could not be located in the dynamic link library libstdc++-6.dll." with both. This was in debug, so I tried release, and I got a similar error, with some other entry point not found.
I searched the forums, and I found suggestions that I should link libstdc++ statically. I inserted -static-libgcc -static-libstdc++ at the lines QMAKE_LFLAGS = and QMAKE_LFLAGS_DEBUG = in the file c:\Qt\mkspecs\win32-g++\qmake.conf. This had no effect at all, even after restarting Qt Creator and rebuilding. If I don't copy the libstdc++-6.dll, it still requires it.
Of course, my simple test program without opencv runs from the exe without needing any libstdc++-6.dll, so that means my opencv build is responsible? I wanted to build opencv anew, but I cannot find any CMake settings referring to libstdc++ !
It might be a clue:
When using one of the libstdc++-6.dll files, the error about a missing entrypoint mentions QtGui4.dll. I have a debug build, so it should be QtGui*d*4.dll, shouldn't it? Are there different libstdc++s for debug and release? Either way, I tried to build release, but it didn't work either, same error
Is there no single person on this planet who tried using Qt with QtCreator and opencv 2.3 together on Windows xp, and succeeded? From searching all the forums and Qt archives, I could not find anyone. I'm ready to do the development in Linux, but I'll need a Windows release sooner or later anyway.
I'm trying to resist the temptation of the dark side, which whispers into my ears to forget Qt, MinGW, g++, opencv and try to hack together something in Visual Basic. Oh, the horrors!
Just FYI, I went basically through the same nightmare of combining Qt and OpenCV. This was my experience:
I downloaded the Qt SDK 4.7.4 with Qt Creator 2.4.1 and installed it, no problem.
I downloaded and installed OpenCV 2.4.2 and not knowing that it already came with MinGW...
I downloaded the MinGW compiler which of course had a different version than the one which came already with Qt
This completely messed up my CMake, even when I explicitly told CMake to use the Qt gcc.exe and g++.exe it also used some stuff from my freshly installed MinGW. Probably because I eagerly added every directory to my PATH variable. What a fool I was!
CMake was not able to generate any useful files, so I gave up and installed the OpenCV superpack, hoping this would make things easier.
6.I spent hours wondering, why Qt and OpenCV from the superpack didnt work properly together. I never quite understood. I had the same errors that other users describe here, like console programs crashing as soon as some OpenCV was included. The strange thing is, that I could start the executable manually from FileExplorer (I added all .dlls you could think of to the project folder: opencv_core242.dll, opencv_highgui242.dll, QtCore4.dll, QtGui4.dll and so on...) BUT I could not launch my little test program from within the Qt Creator environment.
I analysed if there was a problem with my DLLs using depends.exe and found out that even though I configured everything to be in DEBUG using the MinGW compiler, my program still tried to use QtCore4.dll and not QtCore4d.dll... So my best guess was, that it was mixing debug and release version.
I gave up using the superpack and again tried to use CMAKE first and then build OpenCV using the Qt MinGW version AND making sure to setup everything for Debug mode and enable the QT option. But no luck with that so far
I stopped using MinGW and switched over to MSVC2010, which works better. However I am still not able to debug the program since the MSVC2010 debugger engine seems to be missing. I dont really know how to manually add this but I am still working on it
So what I can definitely tell is that using Qt and OpenCV for somebody who has little experience is far from trivial!
You should build OpenCV from source, as you already did, it is no hassle. Note that recent versions of OpenCV can be built with and w/o Qt. Highgui optionally uses Qt! It is your choice if you build with or without Qt.
I used Qt libraries together with OpenCV for long time now. I never went for the SDK, instead I used the libs which are built for corresponding VS version. See here: http://qt.nokia.com/downloads/downloads#qt-lib
You can have it for VS2008 and VS2010, but earlier versions are also available built for VS2005. Old versions of Visual Studio suck so hard, why use them anyway.
Then I never had problems pulling it together in a CMake project. It goes along the lines of:
find_package(OpenCV)
find_package(Qt4 ${VOLE_MINIMUM_QT_VERSION} COMPONENTS QtCore QtGui)
find_package(Qt4 ${VOLE_MINIMUM_QT_VERSION} COMPONENTS QtOpenGL)
...
qt4_wrap_cpp(moc_sources ${vole_module_moc_sources})
qt4_wrap_ui(uic_sources ${vole_module_ui_sources})
qt4_add_resources(rcc_sources ${vole_module_rcc_sources})
You know, the usual stuff.
Five man weeks later you may probably get it run under Windows, while under GNU/Linux it is three commands in the shell.
You might have an easier time configuring Qt Creator with OpenCV. This post shows how to achieve that, step-by-step! It displays several screenshots to aid in the process too.
How to deploy Qt+Boost Application on Mac OS X or Windows platform.
I use Qt Creator + Qt 4.6 + MacOS 10.6
How to compile my application into release to run it on another computer w/o installed Qt libraries?
I ship Windows apps built with Qt and I use the Dependency Walker tool to first determine which Qt and MinGW DLLs are required. For Qt 4.6 apps you'll need to always ship the mingwm10.dll and libgcc_s_dw2-1.dll files found in your Qt bin folder (default location of this will be C:\Qt\2009.05\qt\bin).
Depending on which Qt modules you use will determine which Qt DLLs are shipped - you'll always need to ship QtCore4.dll. If you use networking then you'll need QtNetwork4.dll and so on - Dependency Walker will show you.
Note that you should only ship Qt files found in C:\Qt\2009.05\qt\bin and NOT those in C:\Qt\2009.05\bin - the latter folder contains MSVC built Qt DLLs used by Qt Creator and other tools and, assuming you're building using MinGW, these will not work with your app.)
I install these files in the application folder, which isn't ideal if you have multiple products that use Qt. If you are using the same version of Qt for all your projects then you could install the Qt files into a special folder that is then added to the user's PATH. YMMV and this is a big topic in itself.
For Qt, refer to the docs on deployment (Windows, Mac). Keep in mind that Qt is quite big - if you decide to link statically consider building a version of Qt that only contains the modules you need.
Most boost libraries are header only and thus need no deployment. For those that are not (thread, ...) refer to the respective documentation on building and deploy them like any other library.