@Gojir4 thank you so much

Hi The normal way to find out what is going on is using the debugger. So compile the app In debug mode and start it. When it crashes you should be able to see what it was doing in the call stack. The call stack is the area under the editor window when starting in debug mode As you can see it shows where the program was running. The function list. This should give a hint as to why it does crash.

Hi, @J-Hilk! Looks like i found desired method in QModbusDataUnit class docs. Don't know how i missed it being mentioned in List of All Members for QModbusRtuSerialMaster. I guess digging into Qt docs about Modbus was a proper way to solve this :) QModbusDataUnit::QModbusDataUnit(QModbusDataUnit::RegisterType type, int address, const QVector<quint16> &data) In my case this will be: QModbusDataUnit input(QModbusDataUnit::InputRegisters, 3001, data); Thanks for joining my journey!

@ADR_PT you may want to start using QSerialPort the asynchronous (non-blocking) approach, by using signals & slots. Take a look at the serial terminal example

my compiler is mingw32bit and mongocxx driver build in 64 bit . so thats make problem , i solved it by installing 64bit Qt.

@raven-worx Thank you very much for your time, my issue is resolved :-) It was indeed the debug build causing the issue, and I am using the correct qlmdir to avoid unnecessary imports. Thank you again and have a nice day!

Hi, You might want to check KDAB's KDSoap library.

@JonB Thanks for your insight. I did as you suggested and found one of my local variable's address a nullptr(though not sure where it came from). I changed a few lines of code and apparently, my code works fine now. @Christian-Ehrlicher @J-Hilk thanks!

See https://bugreports.qt.io/browse/QTCREATORBUG-26918

@JonB This is exactly what I was expecting and what I thought of.... These type of games, where you have ingame shops and a lot of inventories... If you left-click an item, you probably buy it from shop or use it, if you right-click, you drop it or sell it :)

Thank you all guys. Your suggestions and expert opinion helped a lot with solving the problem. QT forum is always so helpful. After trying many things here is the conclusion and code is now working perfectly fine I removed the tic toc part time(&start); timer = double(getTickCount()); tic(); It was working but crashing then just to make sure that QImage is not NULL I removed the img = QImage(); // releasing memory with if(!img.isNull()) img = QImage(); Its working perfectly fine now.

@neda The data is in pkt_data as far as i can see from docs so try QByteArray databuf = QByteArray(reinterpret_cast<char*>(pkt_data), header->len); qDebug()<<"data: "<<databuf ;

@Imran-Hassan said in QT image display is not working without declaring openCV namedWindow in windows 10: The problem is solved great, so please don't forget to mark your post as such!

How did you do it now?

@simone-malvezzi No, Qt does not supply a set of measurement conversion tables, that's not its job. You could write it yourself, see if there is any pre-written C++ libraries/tables provided, or possibly grab them off the net, either dynamically or statically. As an aside, you will have to decide how "complete" you want to be. Personally I am great fan of Imperial instead of this Metric rubbish, but even I don't measure in "rods", "poles" & "perches" (e.g. http://www.northcravenheritage.org.uk/NCHTJto2009/Journals/2006/RodsPolesPerches/RodsPolesPerches.html) ;-) Though --- and I'm sure you're fascinated --- in winter I measure temperature in Centigrade but in summer I measure in Farenheit....

@SGaist My data is ready to append. So i append them directly. There are 10-100 QTextEdits. I append 100-200 line to each of QTextEdits. Lines have arround 300 characters. I have one vector of vectors source. By the way, i moved my data source to a different thread. Then emitted signals to append with BlockingQueuedConnection. Gui is responsive now. But its not smooth. I dont know using blockingqueuedconnection instead of queuedconnection is the right way but my gui is responsive while appending strings now.

A quick look on bcrypt's webpage tells me this is not a library, but a program. If you want to have it as a library, there is not support for this out of the box. You need to figure it out by yourself. The general instructions for building are to use make. (Usually, nmake is the equivalent on Windows.) I don't see any instructions for Windows on the webpage. You'll have to look through the README's, etc. to figure it out. cmake and qmake will not help as these will just generate makefiles and not compile anything. However, there is already a makefile, so you don't have to run cmake or qmake to create them.

No it's not, you can see that with its constructors that take a QSqlDatabase parameter. No clear is not called, the destructor is. There's no need to create QSqlQuery objects on the heap.

Hi If the database table type is of type date, it wont like a string formatted as SunFeb2020 so you need to match the toString format to the one expceted by the DBMS.

Hi Thank you for sharing. I don't know anything about Pokemon but its cool you used gif so they are animated and the code looks clean and structured.

@RunThiner There's no need for such a loop. QSerialPort already provides an asynchronous API and if you really want to wait for data to be available, there's a blocking API for that as shown in the QSerialPort details.

@rohit1729 You should read this first: https://doc.qt.io/qt-5/signalsandslots.html void panelB::mouseMoveEvent(QMouseEvent *eventMove) { QString txt; txt = QString("(X:%1,Y:%2)").arg(eventMove->pos().x()).arg(eventMove->pos().y()); emit coordinatesChanged(eventMove->pos().x(), eventMove->pos().y()); //qDebug() << txt; } coordinatesChanged would be the signal.

@Gojir4 thanks, I am trying that right now. I’ve added a 1s delay in my image grabbing thread. Let’s see. Fingers crossed!

Hi You can use https://doc.qt.io/qt-5/qgraphicsitem.html#qgraphicsitem_cast and try cast to your child type if it really is, you can then use its members. so check for NULL and note the docs saying " reimplement the type() function"

@magicstar I have the same problem. Have you find a solution ?

@VRonin said in how to Improve visual and add efects to Qt c++ apps for desktop: P.S. and mi instalation folder size is 12gb Checking everything in the installer is never a good idea. only install the version that matches your compiler +1 See the warning at the bottom of Page 2: https://1drv.ms/w/s!AnaQjhA33g0K0lkIZPVjfsWrcPSI ("Warning: Be sure to only select the build(s) that you want. If you simply tick the version number, you will select and install all available builds, which can take up many 10s of gigabytes! This is especially important on Windows.")

@jsulm You were right. I finally understood what you meant by getting the db at any time. Thank you very much for your help! This is my working code: #include "f1_system.h" #include <QtSql/qsqldatabase.h> #include <QtSql/qsqlquery.h> #include <QtSql/qsqlerror.h> #include <QtSql/qsqldriver.h> F1_System::F1_System(QWidget *parent) : QMainWindow(parent) { ui.setupUi(this); QSqlDatabase db = QSqlDatabase::addDatabase("QODBC", "dataB"); QString connectionString = "Driver={SQL Server};Server=DESKTOP-4K9MAS2\\SQLEXPRESS01;Database=Formula1_BD;Trusted_Connection=yes;"; db.setDatabaseName(connectionString); connect(ui.loginPushButton, SIGNAL(clicked()), this, SLOT(validateLogin())); } F1_System::~F1_System() { QSqlDatabase::database("dataB").close(); } void F1_System::validateLogin() { if (QSqlDatabase::database("dataB").open()) { QString selectUser("SELECT Username FROM Users WHERE Username = '" + ui.usernameInputField->text() + "' AND Userpassword = '" + ui.passwordInputField->text() + "';"); QSqlQuery qry(selectUser, QSqlDatabase::database("dataB")); if (qry.next()) ui.label->setText("Status: You are logged in!"); else ui.label->setText("Status: Wrong credentials!\nTry again!"); } else ui.label->setText("Failed to connect to the database!"); }

@Ovidiu_GCO {SQL Server Native Client 17.0 }; What is with the blank in front of "}"

@JonB This adds a new, blank row at the end of the table model. But you do not set that row to hold your component / text? How to do it? I did not correctly understand what this function does, so if it's not hard for you. You can suggest how to insert text in the first free cell

@Nico1564 said in How to draw on Image loaded in a QGraphicsView: Yeah i know that this work but i need to draw with fonctions. I successed to do that but I don't want to have the GraphicsView at the beginning of the program, and i want to add draws like an Ellipse (and the image) when i click on buttons. These lines could just as well happen inside a button click QGraphicsEllipseItem* testItem = new QGraphicsEllipseItem(20,30,120,70,0); m_pScene->addItem(testItem); In that case, you would create an ellipse every time you pressed that button. I don't quite understand the "I don't want to have the GraphicsView at the beginning of the program" - maybe you could elaborate on that.

Sounds rather like a job for libusb

@Lukadriel Hi, One year passed and still waiting for the proper example. Did they give any tips?

@kshegunov I see now, that answers my question. Thanks.

change progsettings result = Data.Process(); to auto result = Data.Process(); I'm trying to get the 2D array of QString. change: QString progsettings[50][2]; to std::array<std::array<QString,2>,50> progsettings; (you need #include <array>) QString Process(); to const std::array<std::array<QString,2>,50>& Process(); QString ReadProgData::Process() to const std::array<std::array<QString,2>,50>& ReadProgData::Process()