@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

alt text

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.