Most voted "qt" questions
Qt is a framework for developing graphical interfaces written in C++ supporting a wide number of platforms. Applications can also be created with QML/Javascript. It is currently developed and maintained by Digia.
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answer148
viewsList data from two tables in the tableView
What do I do to list two table data on tableView? Sqlite Database(Example): tb_venda tb_produto tb_valor tb_cliente_id (Id do cliente "tb_cliente") tb_cliente tb_cliente_id (id primary key) tb_nome…
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answer312
viewsValidate a Qlineedit to only take Double
I’m using the QDoubleValidator data = new QDoubleValidator(0.00, 1000.00, 2, lineEdit); However, when inserting the actual value in the lineEdit he does not resort to the point (.) as decimal and…
qtasked 10 years, 6 months ago carlosgoes2008 79 -
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answer160
viewsCopy Qvector Local to Qvector Class
Here’s what I’m doing in the nail a Linechart chart chart for a class assignment, I’m having huge difficulties with the C++ language, in some part of the code step by parameter a…
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answer443
viewsHow to plot graphs using Qcustomplot in the main thread?
I would like to know how to plot the serial port data in the Qcustomplot library to keep updating. I thank you for understanding. void serialThread::run(){ mutex.lock();…
qtasked 10 years, 1 month ago Netinho Santos 2,366 -
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answers861
viewsHow to render graphics in Qt applications?
I’m developing a small application to read a serial port. I would like to know how to generate a graph that is updated in real time with two variables, one x (time), and another y…
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answer47
views"Finished" signal of a Qprocess is not called
In my project I have a Main responsible for executing a QThread and on this wheel a QProcess responsible for creating a postgresql backup file. Well the main works properly by calling the QThread…
qtasked 10 years ago Jhonny Pinheiro 186 -
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answer38
viewsQT disable Qpushbutton
I created a form with several Qpushbuttons and turned on a SLOT to each of the buttons. At this moment I have, for each button, a SLOT different. Even if each button performs a different function,…
qtasked 9 years, 6 months ago PhatsAndSmall 71 -
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answers451
viewsHow to change the color of a Qtableview header background?
I would like to know how to change the background color of the headers ( horizontal / vertical) of the Qtablewidget object in Qt . I already know how to change all the headers together, using:…
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answer43
viewsHow to use something similar to Borderlayout in Qt?
I’m doing a project using Qt, and I missed the BorderLayout, Would anyone know if he exists in Qt? If not, there’s one that looks like him?
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answer390
viewsInstalling Qt in Visual Studio
I would like to know how to install QT in visual studio 2015, I did everything, but I can not use it. Whenever I give a #include for example, it says that there is no file or directory. I’ve tried…
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answer87
viewsQt Qdebug does not work (does not display messages)
I own the Fedora 23 operating system and use Qt to develop graphical interfaces (GUI), however my Debugger does not work: I’m trying to print messages on console using qDebug(), but nothing is…
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answer860
viewsQt5 creating a Qaction that calls an information window
I am developing a solution in Qt5.4.2, in my menu bar, when clicking an option, a new window should open with that information. I was thinking about doing one QDialog, but depending on it would get…
qtasked 9 years, 7 months ago Lays Rodrigues 43 -
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answer49
viewsVisual Studio 2015 shows no Qstring content during debug/debugging
I’m using Visual Studio 2015 to develop an application in Qt 5. Everything works correctly, but when I try to debug the code and inspect a variable of type QString, debug does not show the contents…
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answer45
viewsHow to create a mask between a QML image and a Qtquick element
How to create a mask between an image imported to QML (e.g., a png icon, jpeg, svg, etc...), and a user interface element in the background (e.g.: a re-click)?
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answers45
viewsGoogle maps API for desktop, and no internet connection
Does anyone know a way to use API from Google Maps to Desktop without internet connection? I need to plot some items on the map, but it is not always that the user will have access to the Internet…
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answer320
viewsHow to get latitude/longitude of a geo-address using Qt c++ in windows?
It is possible to get the coordinates (latitude and longitude) from a geographical location using only the address, in Qt c ++? I know the Qgeocoordinates, Qgeolocation and Qgeoaddress libraries,…
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answer1063
viewspython command to "grab" text from Qt Designer fields and save to sqlite
Good afternoon. I’m enthusiastic and I’m starting in python. With Tkinter I can send the text of the fields to the database with the function "get()", in gtk, if I’m not mistaken, with "get_text()".…
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answer136
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answer168
viewsString Split in C++
Folks I’m looking for a split on the following String in C++ [ { "Nome":"Gabriel", "idade": 23 } ] I’m doing it this way... I receive this json through a query get and storing in a string to power…
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answers56
viewsVisual programming QT C++
I have a job for college and would like the help of veterans at one point. I want to create a block with inputText, checkbox and combobox frame image. Using for example Qgridlayout is easy to…
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answer28
viewsFiledialog problem in QML
I’m trying to use the component FileDialog in the QML I made exactly the same code that is in the Qt documentation on the link http://doc.qt.io/qt-5/qml-qtquick-dialogs-filedialog.html and this code…
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answer155
viewsAs I call a method of a Qtgui.Qmainwindow class, within another Qobject class in python
I have a class: class MyWindow2Class(QtGui.QMainWindow, form2_class): within the init I have this piece of code: self.scr = ScriptManager(self)…
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answer420
viewsProblem compiling python in pyqt libraries, with py2exe
I’m trying to compile with py2exe, but when I compile from error. Let me give you an example of this error, with Python 2.7 64-bit programs, pyqt4 for Python 2.7, and py2exe for Python 2.7. Follow…
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answer49
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answer139
viewsUse of delete Function - Inheritance of a Qlist
When compiling I get the following error, in Qlist. I’m using Qt 5.6. error: use of Deleted Function 'Vitamin::Vitamin(const Vitamin&)' Current->v = new T(*reinterpret_cast(src->v));…
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answer67
viewsResetting a Qabstractlistmodel
Would you like to know how to reset or clean data from a Qabstractlistmodel? I am using Qt version 5.6. The problem I’m having is when I try to perform an update of the information that is in the…
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answer82
viewsQT - View Webcam on a Qlabel using another Thread?
Hello, I’m doing a C++ project using QT GUI. In the project in question I need to display images of a camera in the window, but in doing so, the performance of the window is very compromised, all…
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answers106
viewsQt project builds on Ubuntu but does not build on Windows
I have a project for college originally produced on the linux platform using Qt Creator and I need to migrate it to windows. I tried to compile but the project has errors in a single header file and…
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answer84
viewsIs it possible to shorten the path of files . h included by file . pri?
I’m trying to separate my application from a small open lib I created, so I put the files on .pri and includes in the .pro, the structure of the folder was like this: c:/projetos/ ├── minhalib │ ├──…
qtasked 8 years, 3 months ago Guilherme Nascimento 98,651 -
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answer72
viewsHelp with regular expression
Hi, I need a hand with Regex. I need to split a string to store in a list, so I’m doing like this. QString a = "strength 0.5"; QString b = "'kernels[1].params.sigma_albedo' 0.02"; QString c =…
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answers31
viewsIntegrate Combobox with Tableview QT
I have a table Courses: create table Cursos( ID_curso int not null auto_increment, Nome_curso varchar (50), primary key (ID_curso) )default charset = utf8; And another registered table: create table…
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answer215
viewsParallel programming Qt C++
I’m starting to learn parallel programming, and I’m looking to compare a program with a single thread with a multi thread. What I thought was to make a very simple algorithm that, in a 1-minute…
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answer216
viewshttp connection to c++ and Curl or any other library
I need to request https and http url. I found several libraries, some easy, some not so easy, but the only one I could install was Curl. I’ve taken several examples, the problem is that in the…
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answers47
viewsNot returning the value when using the QT C++ query
When I use the following query to return the database data code, the following message appears: Qsqlquery::value: not positioned on a Valid record Use the same model code and the same is working,…
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answers33
viewsQcoreapplication::applicationVersion does not "recognize" RC_FILE when using Mingw
I created a file rc (Resource File) simple and added it to the project (winvertest.pro): rcexample.rc #include "winver.h" VS_VERSION_INFO VERSIONINFO FILEVERSION 1,0,0,1 PRODUCTVERSION 1,0,0,1…
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answer559
viewsQstring accents in Qt 5.9 results in bizarre characters
Hi, good afternoon, I have a question I can’t fix at all the code is as follows:.... QTextStream stream( &file ); stream.setCodec("ISO 8859-1"); stream << "<p align=center><font…
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answers72
viewsError building on any protection in Qt Creator
When I try to build on any project in Qt, it gives this error message (test with one of the examples that already comes with Qt) 13:15:37: Running steps for project analogclock... 13:15:37: Could…
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answer108
viewsHow can I create a layout like the image with QML?
I’m learning QML now and I want to create something similar to the image attached, I’ve tried to create something but I can’t manipulate the vertical menu buttons and leave it like the image,…
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answers46
viewsHow to promote Qgraphicsview in Qchartview?
I’m new to Qt Creator, I want to know how to present 2 or 3 graphics on a single screen, I’ve seen some examples that Qt provides, but they don’t show how I want to learn how to do it, please Help.…
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answer169
viewsHow to resolve this ASSERT error: "!" No style available without Qapplication!"" in file kernel qapplication.cpp, line 1054?
When I start an application to display a graph it shows me this error: QML debugging is enabled. Only use this in a safe Environment. ASSERT: "!" No style available without Qapplication!"" in file…
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answers60
viewsQuery return problems [Qt Mysql]
Considering the following table: ID : int Quantidade : smallint PrecoUnitario : float(5,2) I tested the following Query in Mysql Workbench: SELECT ID, SUM(Quantity * Precounitario) FROM test GROUP…
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answer50
viewsHow to know the last element in a Qlistwidget?
I have a Qlistwidget called list_toMerge with some items added, then I created 2 buttons to change the order of the items. The up button and the down button. First look at the code in the up button:…
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answer196
viewsHow to validate the price in Qt?
I would like to know how to validate the price in Qt, as follows: Accepted examples: 10,00 / 100,00 / 1.000,00 = true My code, (but it’s validating true: 10 / 100) bool ok;…
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answer63
viewsUpdate a Combobox after opening Qdialog
How do I update a Combobox after opening a Qdialog? The code below does not update if you have an update in db. I have to close the application and open to show the new data: Dialog::Dialog(){…
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answer31
viewssqlcipher compile plugin in windows
How do I compile the plugin in windows? I’m doing like this: Git Clone sqlcipher - C:\sqlcipher installed MINGW32 - C:\MINGW32 installed msys - C:\MINGW32\msys\1.0 installed tcltk-8.4.1-1-…
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answer743
viewsHow to close the app console?
I run this program with the executable, but it remains to close the console that is open after running, how to do this?…
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answer77
viewsMultiple Definitions in the moc. file of a class
I’m having many Multiple Definitions problems in QT. For common classes, and all classes in our library, the solution was to put the header and implementation in the same . hpp, and it worked. In…
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answers424
viewsQT signal from C++ to QML
I am trying with QT 5 + QML to create an application where after opening the file using the fileDialog it returns a message by a QT signal. The application opens using a QML and initiating a call to…
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answer73
viewsLoss of reference per parameter
I have the following problem, when executing the method insereOP() the instances maq and cli lose their data. So when I call the method atualizarOP, client and machine information do not exist,…
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answer273
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