Did you try to use the patch provided in the report ?

@Milav said in segmentation fault:

the difference between host pc and Embedded target board is only QT source.
Host pc => qmake (qt version 5.4.0 )
Embedded target => qmake (qt version 4.8.7)

You should have stated these settings from the very beginning... :-)

Anyway, could it be possible that you build Qt 4.8.7 for PC (host) and build your example again with that Qt version and run in PC to see what happens.

Finally I changed reading mode to read directly from the data file. It's most faster and just I was care to encode data when reading to keep special charcatars.

Thanks all for your ideas

@Sivamani-V said in How to connect to mysql server in ubuntu 16.04?.:

QMYSQL Driver not loaded. Available drivers: QMYSQL QSQLITE QMYSQL3

This gets asked so many times, here & elsewhere. Googling for your message will bring up many hits. Under Linux/Ubuntu it's usually libmysqlclient or libqt5sql5-mysql or similar which is missing/has dependencies missing/wrong version.

Hi
You are mixing old syntax with lambda which it cannot do.
With lambdas you cannot use the SIGNAL() macro.
Has to be the new syntax.

I used

QObject::connect(&but_submit, &QPushButton::clicked, [&]() {...

which compiled fine and did show the entered string.

But you seems to be using
Qt-4.8.5 at and new syntax first came in Qt5
so i guess that is why you get errors.

So basically, with that old Qt , you cannot do it in main.
You need a QOBJECT based object to send signals to.
In that old Qt, its not possible to connect to functions.
Only to member slots in a class.

You must use that so old Qt ?

@define-qt
You can be more specific using the name of object as identifier in style sheet sintaxe

QLineEdit#ObjectName { border:0; }

JS handler can be added via evaluateJavaScript, and Qt bridge used to provide actual handling via exported QObject

I've considered adding API for C++ event hadlers, but that would require some development effort

yes, calling setfilter will call select using the filter argument as WHERE clause so resetting the whole model

No event loop in my test - that is the problem.

achieve make it work like this:

property string archivo: null function ubicacion(x) { archivo = x; return archivo.substr(8); }

Lo resolvi ya con este ejemplo http://doc.qt.io/qt-4.8/qdeclarativedynamicobjects.html
Lo malo es que tengo que programar varias cosas que con el codigo anterior hacia perfectamente. pero ahora puedo crear las ventanas dinamicamente y cada una es independiente. no estan mas en una lista o cuadricula.

Hi
Main windows is a bit special since it has "central widget".
which there to allow to define areas around it
for Dock windows. That is why we insert widget first.
For all types of other widget we would insert directly.

QWidget* centralWidget = new QWidget();
QVBoxLayout *layout = new QVBoxLayout;
centralWidget->setLayout(layout);
layout->addWidget(st);
setCentralWidget(centralWidget);

seems fine.
For centralWidget , u can then use the Stacked.

My mainWindow code actually looks like:

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{

setLayout(layout);
// that sets directly on mainwin. not sure it does what we think.

You can just single step and see the values to find out why u crash.
Sorry, i cant spot it. Running it helps.
I think u need a setCentral also.

That is the reason no 2 to why i like
UI file so much. no crashing as u can only insert legally when visually :)
And no code to try to spot bugs in.

I think u need
new widget
widget as central
new layout
layout to widget
inset stacked to that layout
and then the page stuff

@Chillax You're Welcome :)

@SGaist said:

QNetworkAccessManager.

ok, i know by Qjson (but is for a 3rd and i preffer use the official) i forget the existence of QNetworkAccessManager.

@Bart_Vandewoestyne said:

we're storing our Qt build in our version management system

This is a strange thing to do, since Qt guarantees binary compatibility between minor versions, but well, you're free to choose. Unfortunately, I don't see how you could decrease the size further, beside deleting the docs, as the libraries are in the /lib directory and they're the next biggest size. Maybe store only the libs that you're using, i.e. these that you're going to deploy. No point in keeping QtXml if you're not using it, right?

The most important thing:

QT += widgets

in your pro file. Otherwise the port itself is pretty painless, see here

@SGaist OK. Thanks for the answer. I'll give a try.