@WynnRostek said in cannot find -lGL:

I don't see where this library is getting called to be linked in. I also have no idea what the library actually is.

Those are OpenGL development libraries. They are required by Qt itself.

This is under Ubuntu 18.04. Can anybody shed any light on what be be going on?

http://doc.qt.io/qt-5/linux.html#requirements-for-development-host

@MAthias_Va said in High performance live chart:

I think I can't use third party as I already crossed compiled my device with only Qt libraries!

You can cross-compile the 3rd party libraries later, right?

@Engelard said in No std::find() in Qt..:

yes it's not offered, and function is black as it would'nt exist or unfinished code, but it works :D

Hover your mouse cursor over #include <algorithm> and press F2. Do you see find() in that file?

@A123 said in New Errors when moving C++ code to QT Creator:

its been used by others for years and it worked perfectly AFAIK with gcc and clang before I started using qtcreator which complained.

Here's my guess: Previously, the assert() macro was disabled. This caused the illegal code to be effectively "commented out", so the compiler didn't detect it. After the migration, the assert() macro was no longer disabled, so the compiler now sees the bad code and (correctly) complains.

See also http://www.cplusplus.com/reference/cassert/assert/. You could make your code work again by defining the NDEBUG macro, but be careful: This will disable all assert()s which might cause other errors to go undetected.

P.S. The compiler is the one that complained, not Qt Creator.

@ManiRon

You can make use of QtSingleApplication.

Some more alternatives.

@SGaist Yes, It seems following code is saving the results:

retcode=SQLNumResultCols(d->hStmt, &columns); qDebug() << "cols: " << columns; if (columns) { setSelect(true); for (int i = 0; i < columns; ++i) { d->rInf.append(qMakeFieldInfo(d, i)); } d->fieldCache.resize(columns); } else { setSelect(false); } setActive(true);

It creates some FieldInfo and appends them into QSqlRecord. But It just send some data like column names not the data (rows). When SQLMoreResults and SQLFetch is called from my code, all the tableData are cleared in the buffer, so that there no dataTable anymore in QSqlQuery object. So confused

@mrjj Sorry, I'm not sure.
I can we able to set common x axis and differenty axises to the each QwtPlotCanvas?
if yes, could you say me how to?
I'm searching for it.

@Annabelle said in Qt Programming Language:

@JKSH said in Qt Programming Language:

@Annabelle said in Qt Programming Language:

Try to get your updated code to affect what's shown in the Command Prompt without making a separate project. If you are able to do this, you will save yourself lots of time in future exercises or projects.

After you edit the code in your original project, remember to save your changes, then rebuild and re-run your program.

That's what I did originally, and unfortunately the resulting text in the command prompt didn't change, it still said "Hello World!".

To clarify: Did you close the original Command Prompt window before editing, saving, rebuilding, and rerunning your program?

Yes.

Hmm, that is strange. However, without access to your PC, it's hard to tell what's wrong.

In any case, don't let yourself be hindered by little issues like this. Be proactive, and keep working your way through the tutorials.

@MScottM said in Need QML advice:

void setValueMsg(QVariant relayMessage){

Qt classes, especially implicitly shared ones, are best passed by const reference const QVariant &relayMessage.

id: Temp
objectName: Temp

Not sure if using a capital letter at the start of an id is a good idea. If it works - fine. But the convention is that capital letters are for QML components only.

Object name should be a string.

Now, the actual reply:

MessageRelay.setValueMsg(valueOutOfRange(messageObject))

Here you are calling a method on MessageRelay so there is no need to use valueOutOfRange here.

Also, this code does not belong inside onValueChanged because it is inside another slot. Here is something that should work:

onValueChanged: { if (value > normalRangeHi) { valueOutOfRange("Coolant Temp", Temp.value) } else if (value < normalRangeLo) { valueOutOfRange("Coolant Temp", Temp.value) } } onValueOutOfRange: MessageRelay.setValueMsg(messageObject)

Note: since you declared valueMsg as a Q_PROPERTY, the last line can also be:

onValueOutOfRange: MessageRelay.valueMsg = messageObject

There might be one more problem ahead: you declare valueOutOfRange signal with one argument (messageObject) but then you pass two in onValueChanged. That is likely going to fail, but I may be wrong.

@J.Hilk @ambershark @dheerendra Hello, I resolved yesterday's doubts, I just Played with "Qfile" and "QstandardPath" and it is done, Solution is below:

1) auto path = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);

By the above part, i got the path where android app's data is been stored and it is not visible in device, it is not visible anywhere except if the phone is rooted.

/storage/emulated/0/

This path gave me the root directory path of an android operating system.

So, i placed a file in root directory and moved it into AppDataLocation.

and atlast i deleted the original file.

You can add the web socket functionality on your own for your project. It is doable.

see if this simple example helps.

MyWidget::MyWidget(QWidget *parent)
: QWidget(parent)
{
this->m_lab = new MyLabel;
this->m_lab2 = new MyLabel;
this->m_lab->setPixmap(QPixmap("/Users/dheeru/myImage.png"));

this->hlyt = new QHBoxLayout(this); this->hlyt->addWidget(m_lab); this->hlyt->addWidget(m_lab2); connect(m_lab,SIGNAL(mypix(const QPixmap*)),this,SLOT(changeMyPix(const QPixmap*)));

}

void MyWidget::changeMyPix(const QPixmap* pix){
this->m_lab2->setPixmap(*pix);
}
======= Custom Label =============
MyLabel::MyLabel()
{

}

void MyLabel::mousePressEvent(QMouseEvent *ev)
{
emit mypix(this->pixmap());
}

Only performance difference is creating the QApplication object or QGUIApplicaiton object in the beginning. Since our intention is to use QStandardItemModel classes, we are forced to do this. If you totally don't want use these model classes, subclass QAbstractLitModel and implement your own data function.

This error clearly indicates that same file is compiled twice in your build. I suggest you to look what are different places this file config.cc is included in your build.

Hi, it still can be drag on Linux :(

Now i'm stuck with this error:

Input:
cd %QTDIR%\qtbase\src\plugins\sqldrivers
set mysql=C:\Program Files\MySQL\MySQL Server 8.0
qmake -- MYSQL_INCDIR=%mysql%\include "MYSQL_LIBDIR=%mysql%\lib\opt"
Output:
Cannot read D:/Qt/5.11.2/Src/qtbase/src/plugins/sqldrivers/qtsqldrivers-config.pri: No such file or directory
Project ERROR: Library 'mysql' is not defined.

Someone knows what am i suppose to do?

@SGaist
It is difficult to change because it is an existing version.
Does changing the QT version resolve the issue above?
Does this version cause the problem I mentioned?

Most likely, the SDK .dlls are not found when you run your application.

How were you able to load an FBX after including Autodesk FBX SDK?

cmake not found is normal in the VS command prompt. You can use the full path to the executable to run it.

@Aaron-Kim So it seems that mingw64 can output libraries with the extension dll. So I lied about that part above.

So if you're sure you are using libraries compiled with the same compiler and architecture then it's something else causing them not to be found.

I see you are using -llibopencv_core400 for a file libopencv_core400.dll. The proper line for that is -lopencv_core400, you drop the lib prefix and the extension suffix.

The second part where you forced a full filename will work too (however it's not a good practice. Hard coded paths are a big reason for that. So along those lines what is the output from either fixing your -l lines or using the second set. You just show the exit error code from the linker. You definitely have a linking problem but without the actual errors it's hard to help you figure out what they are.

Things that cause libraries that "should" be found to not be found:

Different compilers Different architectures Path not set properly with -L Library name not correct with -l

See the Star Item Delegate Example.

@dheerendra said in Is it possible use QML Drawer and SwipeView types as QWidgets?:

QML is no more above the QWidgets. Not is completely different and OpenGL based. You can use QML type and put widget wrapper using QWidget::createWindowContainer(..) function.

Ok, thanx, I read about this and looks like it is possible solution. But:

There are widget based Swipe and drawer.

If you are talking about Qt::Drawer then AFIAK this works only in MacOSX. But I create app for Android. If there is any other widget based drawer - then how to use it in Android?

Did you ever figure this out?

Hi, the ActiveX support in Qt is ancient and should be the same for Qt4 and Qt5, so you should be getting your 4 floats (xmin, ymin, xmax, ymax) in Qt5 also.
Googled and found this so if the app object (the one you create with something like new QAxObject("CT.Application");) has a visible property, try setting it to true. Note: this is just a guess :-)

Did you already check the bug report system to see if there's something related ?

No they are not, Qt's containers are implicitly shared which is not the case of the STD containers.

Hi,

22 ? It's not part of the QSerialPort:: SerialPortError enum values.

Hi,

You don't give enough information about what and how. You should also test against a more recent version of Qt.

That's the idea of my suggestion: trigger the next command only when you received the answer to the last one, not in a tight loop.

@mrjj

Thanks, I'll take a look.

Even when your application is running ?

Since you want to do remote control, then you can implement a REST API for that for example.

Wow, amazing speed and everything 100% correct.
Thanks to all of you!

Hi,

That's a question better asked to the Esri developers providing the SDK.

Hi,

The component linked in that stackoverflow post might be what you are looking for.

Hope it helps