Qt/C++: Icons not showing up when program is run - qt

I've added a QAction to my QToolBar in my MainWindow in Qt Designer (using the Qt Creator IDE) and given that Action an icon (done by "Choose File" and selecting my .png located in the same directory as my project and source code). The icon shows up fine in the toolbar in Qt Designer, but does not show when the project is running. I've had similar trouble when choosing the title bar icon on windows. I've never used graphics in Qt before, is there something special I need to do?
Screenshot:


I found myself doing all the right stuff, adding a qrc file and placing my icons there. When I run the program no deal.
Turn out I was forgetting to run qmake:
Right click your project's name and select "Run qmake". Or go to Build>Run qmake.
Everytime you change something in the .pro file you need to run qmake again. Creating a resource file implicitly adds argunments to the .pro file, so you need to do it.
Hope it helps other people out there.


Did you make a QRC file (that is, Qt's equivalent of a resource file?)
If not, that would explain what you're seeing. The icons will show up in the creator, but not in the final compiled executable. Have a look at this:
http://doc.qt.io/qt-5/resources.html


Also in case of shadow build don't forget to use windeployqt.exe on your application executable file. After that several folders will be added to your build directory. Particulary two important folders: iconengines and imageformats which contain several dlls needed to load and draw the icon.


Have you tried opening up the Project file. For example, my project file is named menu.pro and it contains the following:
TEMPLATE = app
QT = gui core
CONFIG += qt debug warn_on console
DESTDIR = bin
OBJECTS_DIR = build
MOC_DIR = build
UI_DIR = build
FORMS = ui/mainwindow.ui
HEADERS = src/mainwindowimpl.h
SOURCES = src/mainwindowimpl.cpp src/main.cpp
RESOURCES = Images.qrc
The last line (RESOURCES = Images.qrc) is what you need to put in your project file: of course, use the name that you used for your resources file, in my case, it is Images.qrc.


While adding icons use "Choose Resource" option instead of "Choose
File" option.
Right click your project's name and click "Run
qmake".


Also make sure you don't forget to include the qrc file in the code (e.g. in main(...)) with Q_INIT_RESOURCE(MyIconResource);
This can also lead to missing icons in the final exe.


I also faced such a problem. In my case, I closed qt creator and deleted the build folder (something like build-projectname.. ). Then restarted qt creator. Then magically my icon showed up on running application.
I often use this trick when qt doesn't behave well.

Related

QtCreator Build doesn't update UI changes in design form

My Qt project uses shadow build.
When I change in MainWindow form ( .ui file), I build the project but my program doesn't update GUI.
If I rebuild all, GUI will be updated. But rebuild is very very slow.
I try creating a new project (an empty QMainWindow with some labels), I modify some texts. I build and GUI is updated.
How can I use shadow build correctly, without a rebuild of all my project?

The same issue occurs if the *.ui file name is changed.
For example, Changing yourUi.ui to myUi.ui.
If that is the scenario, then the ui_*.h should also be changed, that is, yourUi.ui to ui_myUi.h.

close Qt creator, go to your project directory and delete the .pro.user file, open the project again and this time Qt creator will ask you to configure your project by choosing the kit you use to build your project. Select the appropriate kit and press the "configure project" button. Apply your shadow build. I hope it will work.

Have you tried to just run qmake (Build -> Run qmake) ?
Edit
As suggested by a comment, I copied the comment to preserve it.
It seems that QtCreator correctly rebuild the .h file of the ui in the shadow build directory, and then include the ones in the source directory, which is not regenerated. I don't know if this is a bug or an intended behaviour, but a quick workaround can be to build the project in the shadow build directory, copy the generated .h files back in the source directory and rebuild again. This work with my simple project, don't know if can be workable also for bigger and more complex project. Or do not use shadow builds

How to tell QT creator to parse .pro file when I build after changing it?

I'm using qt 5.3 under windows 7. Every time I edit the .pro file I need to clean up Makefile file under output/building folder to make it re-parse the changed pro file. I want it automatically detect the change when I hit build or run.
Is there some config I miss-set?

Three ways to re-parse the .pro file:
Right-click the project name in the Project pane (the topmost item) and select Run qmake
Click the Build/Run qmake menu option
Edit the .pro file, press Ctrl-S, and let Qt Creator automatically reparse it
It sounds like the third option is what you want and it's not working for you. It has traditionally been flakey and I never rely on it -- I use the first technique, right-clicking the Project and choosing Run qmake.

Using Qt Creator in QML Design mode, how to reference an image using qrc path?

So, we have an embedded Linux system running Qt and we compile all of our icons (.png format) into our executable using the resource file. The problem is that I want to be able to use the Qt Creator QML Designer to visually see our screens as we are laying them out, but it only allows me to select a relative file system path (i.e. not a path to the resource). If I go to edit mode and put the qrc:/image.png it works in run time but the image doesn't show up in the QML Design mode. Has anyone ever done this or know if it is possible?

There is at least a workaround:
Put everything in the resource file (the qml files and the icons), and when you'll edit the file in Qt Quick Designer, all paths will be relative so the icons will be visible.
Everything is described there: Managing resource files with the Qt resource system
And to avoid deploying the qml files, you'll have to remove/comment the following line from your .pro:
DEPLOYMENTFOLDERS = folder_01
and replace it with:
OTHER_FILES = <list of qml files>

QT/C++ on MAC - Application Icon doesn't set

Weird problem I'm struggling with. On the same folder as my "*.pro" QT project file I have a Resources/myIcon.png.
I am trying to set that as the Icon for my built application, running on OSX. I read the documentation and it suggests to put a "ICON = " in the .pro file. I did that, but for some reason, the icon IS copied over the the resources folder inside my app's content, but the .pfile's icon field remains empty. Even when I change it manually to "resources/myIcon.png" it will not work.
What am I doing wrong?

Manually delete the generated app bundle. Run QMake followed by Rebuild All is not sufficient!

Don't set the full pathname within the application bundle for the icon file in the Info.plist. Just set the filename. Mac OS knows to look in AppName.app/Contents/Resources for it.
And yes, it must be an ICNS file as far as I'm aware. You can use the 'Icon Composer' utility that is part of the Mac OS development tools to create an .icns from a .png.

Are you referring to the icon which appears in the dock? I added a .ico to my application's resource file, then set it as my icon with the following call
QApplication::qApp()->setWindowIcon(QIcon(<resource path>));

Qt designer does not update the gui

Someone wrote out a GUI in Qt designer earlier and now I have to modify some small parts (i.e. add a button/functionality).
Premise:
I add the new feature/make any modification to the .ui file in Designer.
I can go to edit mode and see that this makes changes to the xml format of the .ui file
Problem:
When I build and run Qt, the old version of the .ui is what is shown (without my feature upgrades).
I tried cleaning everything and running qmake, but to no avail.
Any ideas for why this could be happening?

I had the same problem and it was solved when I disabled "Shadow Build" in "Projects" mode.
UPD:
Still receiving upvotes for this answer makes me sad for 2 reasons
it is trivial
the issue is still there after almost 5 years

I could solve this problem wihtout change Shadow Build configuration.
In my project I want to build with output files into build-ProjectName-Debug
But the QtCreator is not smart to check if are not files moc_FileName.cpp and ui_FileName.h into build directory.
This problem occur because if these files moc_FileName.cpp and ui_FileName.h are into project directory the QtCreator uses them and does not recognize any modification on .ui files.
The solution to this problem was easy to me:
Remove all moc_FileName.cpp and ui_FileName.h from project directory and Rebuild.
These files will be created into build-ProjectName-Debug and all modifications will be there.

When you change a .ui file, someone needs to run uic.exe on the file to generate a header file. For example, for a window called MyWindow.ui, this will generate a file called ui_MyWindow.h.
This is then what is used when the application is rebuilt.
You don't specify how you are building or on what OS, so it is hard to help you on that end. If you are using Visual Studios it is possible to integrate your .ui files into your projects so that when you change any .ui file, all the generated files will be recreated automatically. The same is possible if you are using .pri files.
In any case, I would run:
uic.exe -o ui_yourfile.h yourfile.ui
Please change the names of the files to the ones you are using.
uic.exe can be found in your Qt bin directory.
Then once you have the generated header file, try to find where it goes in the build directory. Then rebuild.

This is what helped me personally, add to qmake file:
UI_DIR = $$PWD

I solve this problem by cleanthenbuild.I find that ,if I checked Shadow Build,qtCreator will use the old .obj,other than generate new .obj even if the ui_xxx.h had been changed,to generate .exe when debug agin.My enviroment is qt5.5 + msvc2013.

I had the same problem and was able to solve it by deleting all the Makefiles in the build directory, then rebuilding from scratch. For some reason, these files are not deleted when you run Clean Project from Qt Creator.

Same problem for me.
Nothing works until I changed the installation from Qt 5.0.2 (MSVC 2010) to Qt 5.0.2 (mingw).
Now it is working again...wired

I experienced the same problem: no ui changes appeared after building.
The problem as mentioned above is that the ui files are not getting remade.
Unchecking shadow build solved the problem for me but only once. After that I could not see subsequent ui changes again. So I rechecked shadow build and deleted the existing shadow build folder. This works consistently now, as long as I delete all the build files. But that's lame. It should be able to detect ui changes and remake the files.
I think this should be logged as a bug in Qt Creator/Designer.

I deleted all auto gen file in source folder. when I unchecked shadow build, auto gen file was created in source folder. after when I checked shadow build, compiler only use source folder's gen file. So I deleted all auto gen file(ui_, moc_) and then ui was updated always.

In my case, the problem was caused by a rename of the .ui file. Qt Creator didn't update the #include for the header file "ui_[name_of_ui_file].h" in the .cpp file corresponding to the form. Anyway, cleaning up all the "ui_*.h" files in the shadow build folder solved the issue (I guess unchecking "shadow build" in the Project tab would produce the same effect).

Have you been playing with the system date or time or they were different from those of your fellow's computer? I was changing the time to some hours later for testing purposes (and compiling the project in the meantime) and after restoring it to current time, the compiled files were not updated because they were newer than the compilation time. Running Clean did not delete those files. Unchecking the Shadow build option only gave me crashes and an untraceable 0xc0000135 error. Deleting manually the moc_*.o and *.cpp files with future date/time from the building directory and compiling the whole project again was the solution for me.

Add the following line into .pro file
UI_DIR = $$PWD

As mentioned above, the ui files are not getting recreated. For me, the easiest solution is just hitting Rebuild instead of Build. No need to go into project submenues each time.
As long as your project is not too big, this is OK (apart from this is an anoying bug that qt has for long years now)

I had the same problem and then realized that I have modified the .pro file manually: that is I made "illegal" thing - moved mainwindow.ui under DISTFILES (by default all ui files are grouped under FORMS).
Returned back to FORMS and now everything works fine

This happened to me when I deleted elements from my form in the designer, but still had those elements referenced in the .cpp file. After I deleted those references in .cpp I was able to rebuild and the compiler stopped complaining.

Resources