Questions tagged [qt5]
Questions specifically for version 5.x of the Qt library. If your question applies to other versions of Qt, use the tag [tag:qt4] or [tag:qt3]. It is recommended to use with the tag [tag:qt].
8,770
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How to use pyqtSlot() without @
I need to create a method in a foreign PyQt5 window class at runtime (that will be called later from a different thread with QMetaObject.invokeMethod()). Therefore I cannot use the decorator style. Is ...
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23
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"make: *** There is no rule to build target "sub-mysql". Stop." error when trying to create a MySQL driver with Qt
I'm trying to install the QMYSQL driver on Ubuntu 24.04 LTS with Qt version 5.15.3, but I'm running into some issues.
Problem:
The sqldrivers directory only contains the SQLite driver, and I'm missing ...
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-2
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39
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QSqlQuery is not meant to be copied
I have defined a QSqlDatabase as follows:
QSqlDatabase m_db;
And use it repeatedly for each new query as follows:
QSqlQuery query(m_db);
query.prepare(querystring);
success = dbquery(query,...
- 4,490
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33
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Install Qt5 libraries on Debian 12
I would like to install the Qt5 libraries onto Debian 12, but I do NOT want Qt Creator. I just want to be able to compile a C++ app which uses Qt5. And I would like to use packages from default ...
- 4,490
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Does Qt UI freeze imply UI Thread is stuck in VSyncFrameAdvanceService::waitForNextFrame()? [closed]
If the UI of a Qt/QML application appears frozen (i.e. there is no change within the window over time and clicking anywhere has no effect), does that necessarily imply that the main UI thread of Qt is ...
- 4,521
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(Qt version 5.15.3) This application failed to start because it could not find or load the Qt platform plugin "xcb"
when i run qtcreator like this ./qtcreator, the error come out
enter image description here
and the ubuntu version is 22.04 ,qmake version is 3.1
enter image description here
i have tried many ...
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53
views
Data sent from CPP causes interface crash in QML
first of all, I have a problem like this. I want to transfer the data to the QML side with a signal from C ++, but after a while my interface crashes without giving any error. I can't find the reason ...
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39
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Building Qt 5.15.1 from source code but facing issues with configure
I am trying to build Qt 5.15.1 by cloning the repo and following the README but I came across an issue an issue.
Everything went seemingly well till the step where I needed to run the configure file ...
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61
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Qt QModel view use QSortFilterProxyModel fucntion is so slow，something wrong？ [closed]
I use Qt Model view with QSortFilterProxyModel
QListView with checkbox and name ，only one column
QStandardItemModel setData ,100w row
use QSortFilterProxyModel function setFilterFixedString
and add a ...
- 11
-1
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48
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How to create customized barcode in qt c++?
I'm using qt 5.15
i have to develop application for Code 128 barcode generator and now I want to reduce the barcode strips. How do I create customized barcode strips?
My code is below,
Code128.h
#...
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2
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1
answer
44
views
Q_DECLARE_METATYPE results in assert failure after upgrading from Qt 4.8 > 5.15
I have a large file which uses these macros:
Q_DECLARE_METATYPE(boost::function<void()>);
Q_DECLARE_METATYPE(boost::function<void(const QPoint&)>);
But sadly after upgrading from Qt 4....
- 53
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24
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Visual Studio Code doesn't display visualized Qt5 objects on Linux
Using VSCode 1.85.2.
I have qt5.natvis on my Linux CentOS 7, and my launch.json file includes the following properties:
{
...
"visualizerFile": "/path/to/qt5.natvis",
...
- 605
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31
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In QT6.5, when using QGraphicsView to center an image, the white space outside the image cannot be displayed, resulting in a centering failure
As shown in Figure 1, I want to implement clicking on the green rectangle to jump the green rectangle to the center, and if the green rectangle is closer to the border, it should be centered and ...
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3
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64
views
C++ with Qt5 : lock a common mutex before calling the actual override implementation of a method
I have an abstract class like this :
class Thing
{
public:
Thing();
virtual ~Thing();
static QMutex s_mutex;
virtual void load() = 0;
virtual void translate() = 0;
virtual ...
- 1,153
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1
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13
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Non-symmetric mutex
I have an unknown number of processes that create independent data, and one function that modifies all existing data. I need to be able to prevent the modification of data when it is being created (or ...
- 1,153