I have gotten the latest QWT 5.1.2 for QT 4.5 and managed to get it to complie. I am now trying to get the plugin to work in QT Designer (with VS intergration). I have placed the plugin files into the plugin/designer folder, but when attempting to load, I hit this error
Cannot load library qwt_desginer_plugin5.dll: The specified module cannot be found.
I've done some search on this issue, one page which suggest moving the plugin to the VS intergration folder - which does not exist for Program Files\Nokia\Vs4Addin.
My QT Designer is a debug-and-relase build. (That is, if I use a debug build of the plugin it would complain that it is expecting a release).
qwt_designer_plugin5.dll depends on qwt5.dll, so:
Additionally to placing "qwt_desginer_plugin5.dll" in "plugins\designer" directory, you must put qwt5.dll to some place where windows loader can find it (at example, you can put it in "%QTDIR%\bin" directory)
It appears that I have to place the generated dll into the qt\bin folder for the designer to load the plugin
You may place it everywhere in the PATH. Also the same dir as the executable program works.
You can see how dll libraries are loaded.
Related
I use QtCreator + mingw.
I have compiled QSQLITE2 plugin. I simply entered plugin directory in Qt source code:
c:\Qt\Qt5.2.0\5.2.0\Src\qtbase\src\plugins\sqldrivers\sqlite
and I built it with my sqlite 2.8.17 that I have locally (as dll and header):
qmake "LIBS+=-Lc:\projects\lib -lsqlite" "INCLUDEPATH+=c:\projects\include"
make
make install
Everything builds okay.
Now, I have another DLL (also implemented as Qt plugin, a custom one), which makes use of QSQLITE2 Qt plugin. My own dll is also linked to sqlite.dll. So it looks like this:
my.dll depends on sqlite.dll
%QT_PLUGINS%\qsqlite2d.dll depends on sqlite.dll
my.dll uses qsqlite2d.dll through Qt's plugin engine
myApp.exe loads my.dll
Problem is that my application cannot load my.dll, because of invalid location access or something like that. I don't know any details and that's the problem.
The sqlite.dll is in the application directory when running it.
When I run application in debug mode, it crashes in some assembly file, but in stack trace I can see that it's somewhere inside sqlite.dll, in sqlite_step symbol. That's all I know.
Note 1) I have another plugin dll, the my3.dll, which uses QSQLITE plugin (it's for sqlite3) and is linked with sqlite3.dll and this one loads just fine. I have compiled QSQLITE plugin myself as well (even there was the one provided with Qt, that's because Qt linked statically to sqlite3 and I wanted it to link dynamically to sqlite3.dll).
Note 2) Both plugins work just fine under Linux.
Any hints what might be wrong? What else can I check?
EDIT:
I've just performed a test: I deleted my.dll from plugins to avoid loading it at all. Then I added code to main.cpp:
QSqlDatabase::addDatabase("QSQLITE2", ":memory:");
Thing is, that it also crashed, with the very same stack trace (at this very line, I debugged it). Thus I think there's something wrong with sqlite2 Qt plugin, but I'm still unable to tell what. I looked up for other sqlite.dll, I just downloaded the one from sqlite.org: http://www.sqlite.org/sqlitedll-2_8_17.zip - so it's official build, but it's the exactly the same file I had and it also fails the same way.
It turned out that qsqlite2d.dll cannot be linked sqlite.dll, because sqlite.dll is not compiled in debug mode. After recompiling application in release mode (thus using qsqlite2.dll, not qsqlite2d.dll), the plugin loads correctly and works.
This makes sense, but just one more thing that bugs me - qsqlited.dll (for sqlite3) had no problem linking with sqlite3.dll. No matter if I compiled debug or release - the single sqlite3.dll worked with both debug and release plugins. Anyone has an idea how is that possible? Please comment if you do, I'd appreciate it.
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.
I have wrote a Qt Quick Desktop application in c++ qnd Qt Creator(QML) on Windows7. Now I have to deploy it.
I'm using Qt Quick Desktop Components plugin in my application, I've installed it according to these instructions, and I'm using it with:"import Qt.labs.components", as written there.
I tried adding to the .pro file:
QML_IMPORT_PATH = C:\QtSDK\Desktop\Qt\4.7.4\mingw\imports\Qt\labs\components
but I saw it's working well without it, and I removed it.
I've read a guide how to deploy such an application here, and followed it; I have now a deployment folder, with: the .exe file, the needed dll's, and a folder hierarchy like:Qt/labs/components.
in components I put the styleplugin.dll(for desktop components), and a qmldir file, with the content: plugin styleplugin, excactly like in the doc.
but when I'm runnig my application.exe from the deployment folder in another computer, I'm getting a white, empty window, means: It didn't find the .dll file.
Should you explain me please what's wrong?
I know two reasons, when app can not load plugin dll:
Some of dependecies of the plugin dll are missing or can not be found and that is why it can not be loaded. Qt Creator or Visual Studio environment can be different than the system one. For example, your IDE can modify PATH environment variable. Check plugin's dependencies availability with Microsoft Dependency Walker tool in the same environment where you launch your app.
App can not find plugin in standard directories. To check this you should specify plugin import directory explicitly:
QDeclarativeView *rootView = new QDeclarativeView()
rootView->engine()->addImportPath(QLatin1String("path/to/your/imports"));
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
I was successfully able to compile and run my Qt application. However, when I move the .exe file outside its original path, I found out that I have to manually copy the Qt DLLs (e.g. mingw10.dll, qtcore4.dll). Is there any dynamic way to link these libraries with my application?
I think you mean you want to "statically" link these libraries with your application.
Basically this means that everything will be rolled inside your exe, and you will have no need of those dlls anymore.
There are advantages to to static linking, but there are also disadvantages as well. You should be absolutely sure that this is what you want to do before you go this way.
Check out this link which explains the difference in depth Dynamic Linking vs Static Linking
As for your specific issue, if you are sure you want to use static linking you will have to change your Qt setup to be built statically. By default the Qt distribution is setup to use dynamic linking. There is a handy guide for that here.
Basically when you setup the build you have to run "configure -static" to change all the project settings to use static linking instead of dynamic linking. And then build Qt over again.
You should also verify your Qt license. If you are using the Qt LGPL license and you want to to link statically you will have to include all your object files (.o and .obj) as Mihai Limbășan wisely explained in his comment. If you have bought and paid for Qt, then you have no problem.
If the DLLs are on the PATH for the application, then they will be found and work. So, you could add where your Qt binaries/dlls are into the %PATH% environment variable. If you're going to create an installer for your application, you'll need to either package these libraries in so they're in the bin directory - or you'll have to expect every user to install and possibly compile Qt themselves (hint: go with the first option. :) )