Cannot find correct file called qtnetwork4.dll - qt

Guys I've written app in qt and when trying to run it (double click on *.exe) I'm getting error that this application cannot start because qtnetwork4.dll isn't available. I've searched my drive and I found few files with this name (and copied one by one every time trying to run my app) but none of them seems to work. How can I solve it?

place into your *.exe - folder appropriate dll-s from %QT_PATH%\bin\

There is an app called Dependency Walker that will let you know what functions in qtnetwork4.dll are being used in your program. It can be found at the following:
http://www.dependencywalker.com/
All of the DLLs your program use will be from the same installation as the qmake.exe that is used to compile the program. If you are using Qt Creator you can see where the qmake.exe your using is located by going to:
tools->options->Qt4
Get the DLLs that are located at the path displayed here to make sure they will work with your program.

On windows, DLL are looked for in folder where executable lies, then using "PATH" environenment variable.
In your case, you want to put your dll along your executable, taking them from the sdk you're using to compile
The following page provides a lot of additional information on the subject (example, plugins, strategy for building installers)
To force using QtNetwork and linking it, you have to put
QT += network
in your poject file.
If you're sure you're not using it, you can use
QT -= network

Related

QT deployment doesn't work missing entry point

I'm working on my second application in QT and i'm trying to deploy a rough copy for testing. It would not run on a test computer, runs with no problems on mine, giving the error "Procedure Entry Point _ZdaPVJ not found in QT5core.dll". So to make sure that was not my program messing things up, i created a blank test application, compile it for release, moved the test.exe to a different location, run windeployqt --release test.exe, it created all the dependencies and folders. clicked on test.exe run with no problem. grabbed the folder recently created took it to the other computer and go the same error.
Is there something that i have forgotten since i compile my first application? Did i changed some setup somewhere without realizing it?
frustrated...
Perhaps you can check if your problem is related to different versions of the dll existing on your system and the wrong one is being loaded:
QT Release build DLL procedure entry point error
https://forum.qt.io/topic/26707/the-procedure-entry-point-cound-not-be-located-in-the-dynamic-link-library
As is suggested in the latter link above (towards the bottom), you could try to use dependency walker to determine from where the dll is loaded. Or use static linking with the licensing issues that causes (also see the latter link above).
And throwing in a final link on using Qt's Window's Deployment tool: Qt deployment; the procedure entry point ... could not be located

How to add an external library to QT?

I am trying to create a project assosiated with the SimConnect SDK.
I am new to QT, and in Visual Studio, I just had a SimConnect.h file, a .lib file, and a .dll file, and I managed to make it work. Now I am trying to create a C++ widget project, using the same SDK, but in QT.
I put the header file in my QT project's folder, where the other default code and header files are located, and then I went to the project and added them as existing files, as I read in Google. I'm having problems with the actual library.
I've been searching Google for a guide on how to add a library file to the project, I did some things I saw on the internet, like the LIBS line for example, but I probably did it wrong, even though it looked very simple.
I am not sure where to drop my dll/library files in the project directory, maybe the problem is I always put them in the wrong spot.
The furthest I got to, was an error message saying "Unresolved external symbol", and a red writing saying ".obj file not found" on every function I tried to use from the SimConnect functions, which probably means QT couldn't find my library/dll file.
I also tried to add the libraries from the "Add library" option in the project, but that didn't work too.
EDIT: it also warns "warning: LNK4272: library machine type 'X86' conflicts with target machine type 'x64'" maybe it has to do something with it.
(Posted on behalf of the OP).
Solved! My problem was my machine was set to 64bit, while the library was set to 32bit, so I downloaded the 32bit kit, and ran the project through that, and it worked!

Getting an all-white screen on deploying Qt Quick demo app Minehunt

To test the deployment process I am trying to deploy the included demo app Minehunt. I am able to get it to run, no crashing or errors, but the screen is all white.
I believe this generally means that I am missing plugins. Dependency walker reports no problems, and I even tried including ALL the plugins from the Qt MingW plugins directory, but no such luck.
Here is what I am including so far; Can anyone advise what else I need to add to get it to run?
Your dlls don't look bad at all. I think, too, that it's your plugins. Even if they are there, there is a good chance, that your program don't find them. Qt is a bit picky where to look by default. You might try qt.conf. This is a small textfile you must create in the folder where your executable lies. It contains the path to your Qt plugins.
For instance, in one of my projects I have the followin folder layout:
Appfolder
plugin
qt
plugins
imageformats
sqldrivers
myapp.exe
qt.conf
...many dlls...
Then I added a qt.conf file to the Appfolder, which has the following content:
[Paths]
Plugins = plugins/qt/plugins
My program is Qt 4, but I don't think this aspect of plugin deployment changed in Qt5.
All my qt dlls are in qt. And I add the following PATH: SET PATH=.\plugins;.\plugins\qt;%PATH%. Works like a charm on any Windows I ever tried.
Edit:
I then created a .bat file, which does:
SET PATH=.\plugins;.\plugins\qt;%PATH%
cd Appfolder
start myapp
This was an ugly quick fix, which I did not have the time to replace with something better, yet.
If application runs and shows blank screen then that usually indicates two things :
All the dependencies (dlls) are probably present and detected properly.
Most probably whats missing is the presence of qml files at the correct location.
In your main.cpp check the path of qml file which you would have given, and see if relatively that folder is present at the same location corresponding to your executable.
Also, instead of running the executable by double clicking, run it through the command line. It might print some messages if it is not able to locate some images/files/other dependencies etc according to the specified paths.
Edit 1 :
Add this flag in the .pro file :
CONFIG += console
It will give the exact debug message in a console once you run the application.

Problems with QT 5 deployment

I've attempted to follow the instructions on deploying Qt to Windows, but I am stuck on step number 1. In it, it tells you to:
cd C:\path\to\Qt
configure -static any other options you need
Unfortunately, I can't get the Qt DOS prompt to recognize the "configure" command despite attempting to use it in virtually every folder under my Qt installation. Does anyone know where this command is store? Everything else about my project is working great with Visual Studio, but I just can't seem to figure out the deployment.
I've Googled the crap out of this and tried both the Qt and the regular Windows command prompts. Any help would be greatly appreciated!
Thanks
EDIT: For clarity, I have tried dragging all of the .dlls needed to run my program (by running it and finding the ones I get errors on), but all that happens is I stop getting errors when trying to run my app. If I double click it with the .dlls in the same folder, nothing happens at all.
Are you sure you need the static Qt build? Note that you must static build the actual Qt framework for that, and only after that you can build your application.
If yes, make sure you have the Qt source code, because configure is part of the source code of Qt, it's a tool that configure the Qt build.
The step refers to path of Qt Source directory e.g. C:\QtSDK\QtSources\\
As you can see in qt5 source tree there is a file configure.bat
You need to run that with static option, so it will configure Qt for static linking.
Then you need to re-build Qt to make your new configuration to take effect.

OpenGL Widget works in creator but black when launched from .exe

I have been working on a Qt OpenGL project for a bit now for some school work. I had to re-build Qt 5.0.1 for my windows machine so I could use OpenGL proper. At the end of this project I need to turn over the files and any executables, so I figured I could take the release .exe and stick it in a .zip for use.
I followed instructions online of making sure I place any needed .dll's into the .exe's dir. For my project there are 10:
icudt49, icuin49, icuuc49, libEGL, libGLESv2, Qt5Core, Qt5Gui, Qt5OpenGL and Qt5Widgets
I took these files all from:
C:\Qt\Qt5.0.1\5.0.1\msvc2010\bin
on my system.
Issue is the .exe will run and I get the UI and all. But the OpenGL scene is just black. I can still click objects in the scene, evidently zoom in and out and all that. I assume thats just the Qt translating the commands still. But nothing is visible. I'm unsure what the problem can be because it all works fine when launched from the creator.
EDIT: So, with all the dlls in the release folder, running the project from within creator will also have a black screen, when I remove them, it runs well. So perhaps one of the dll's is just wrong?
Also:
I looked online about publishing with Qt Creator and found not too much aid, said I should start from completely rebuilding Qt Creator staticly, but I'm sure the guide I had followed did this, however I still can't publish from the build menu, so I stuck with the above method.
I suggest, that you open every of the DDLs in your Zip file with Dependency Walker (http://www.dependencywalker.com/). It should display information about dependencies from one of your QtXXX.dll files to other files. If one of the dependencies is missing, you know where to look next. You can also try to open your executable with Dependency Walker. I haven't used the program for a long time so I don't remember if opening an executable is the only way it works. Anyway, here are the reasons why you might want to use the tool: http://www.dependencywalker.com/help/html/overview_1.htm
This question might also be helpful:
At least one module has an unresolved import due to a missing export function in an implicitly dependent module
Good luck!
So the ultimate issue was the use of the correct DLLs. Using something like DependenyWalker can help you to note which DLLs may be missing, however it did nothing in my case.
I had installed Qt once, and also rebuilt, uninstalled and re-installed it. However all the libraries it was calling from as no longer in C:\Qt\Qt5.0.1\5.0.1\msvc2010\bin as expected, it was calling from the github repository where I built it C:\Users\User\Documents\GitHub\qt5. Once this is sorted out, it still required a framework folder and then it works as expected.
1) Copy the correct DLL files to the release folder of the build.
2) Create a folder in the same dir as the .exe named "platforms". (Note: elsewhere has said create plugins>platforms, but this will not work with newer Qt versions)
3) From the same source you got the other DLLs, copy qwindows.dll to the platforms folder you created.
4) Run the executable and enjoy.
As long as the system you're running on is capable of your OpenGL structure, it should be fine.

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