Hi, Are you sure your database connection is still opened when arriving in the cleanup function ?

@JKSH Not applicable because I have other event sink classes. Also, I use the SLOT string because (for the sake of keeping this post clear, I didn't demonstrate that) I have file-open scenarios too: void OnSingleSelect(const QString &file) and void OnMultiSelect(const QStringList &files). They don't share signatures, so either I need to template-ize (which doesn't work well w/ signals&slots), or to repeat and tweak the helper function. Wait: will selectedFilter trigger setDefaultSuffix along with selectNameFilter? Didn't find evidence in the source tree. Also again: Linux Qt 5.6.1, selectedFilter doesn't setDefaultSuffix. Call chain according to https://code.qt.io/cgit/qt/qtbase.git/plain/src/widgets/dialogs/qfiledialog.cpp : QFileDialog::getSaveFileName -> QFileDialog::getSaveFileUrl -> QFileDialog::selectNameFilter -> QFileDialogPrivate::_q_useNameFilter, which doesn't seem to be doing the work (at least, in my case) after the user clicked OK.

@jsulm Thank you

@J-Hilk Thanks! Hope it can be fixed soon. @jsulm Same thanks!

@texasRanger Why do you think you need an additional event loop? From your description I don't see any need for it. If file is changed you will get a signal from file watcher. You just need to make sure parsing of that file does not take too long.

Your code shows a lot of ignorance of how Qt works, as they point out, I recommend you read the docs urgently. Here no thread is necessary, it is only necessary to use the Qt event loop. Forget about sequential programming (Qt hates while true since they are not needed). You also do not know what the Qt signals are and how they are used. Also you do not understand the advantages and restrictions of threads, it is not safe to access and modify variables in different threads as you try to do.

@JonnyQB Hi You declare it like Punkte * punkten; Then some place else you must do punkten = new Punkte(); ( not in .h) Often the constructor is a good place.

Hi, Where do you get that ID ? You'll click on the action, get the ID and then call the slot ?

@Kalado said in Connect() uses wrong emitter object.: Look at some code: //A.h class task2 : public QWidget { Q_OBJECT public: task2(QWidget *parent = 0); ~task2(); protected: void mousePressEvent(QMouseEvent *event) override; signals: void myWidgetClicked(); //A.cpp void A::mousePressEvent(QMouseEvent *event){ /// use the respective classname emit myWidgetClicked(); } If ur using Classname as task2 , use void task2::mousePressEvent(QMouseEvent *event){ emit myWidgetClicked(); } Thanks,

difference between exec() and show(), Only QDialog have exec() Qwidgets have show. When you call show on a Dialog, it becomes visible but do not wait for input. example mainw::func() { MyDialog *dia=new MyDialog(this); dia->show(); int a=0; // this code is run the moment dialog is shown on screen, } using exec() mainw::func() { MyDialog dia; dia.exec(); int a=0; // this code is run only after dialog is dismissed. } The version of dialog where u call show() could be called floating so when user click ok it should emit signal that something should happen. ( to maiwindow ) The exec() version will report back the result ok/cancel/closed at once. learn when to use QObject, QWidget, QFrame QWidget is often used if making own widget. QFrame is used if you just need something to draw a frame. If you use Designer you can check out the Widgets that are available. QDialog is useful for any type of windows that pop ups up or open via a menu. I have to set anything inside Register. Yes, Register should be able to give the data back. the widgets inside are private so you need a function to return the data. You might also need to call http://doc.qt.io/qt-5/qdialog.html#accept in your Register buttons clicked slot.

@jsulm Thanks, I'll give it a try.

@VRonin Thanks for your input - there seem to be some misunderstanding. I can not and do not want to wait for the acknowledge of the server as a trigger to sent the next log message - this is against the idea. Log messages need always to be sent, regardless wether the server acknowledges or not - imagine the server even does not acknowledge. Every message sent has an ID# that is incremented by one for every new log message sent. The server acknowledges every message with returning the ID#. Looking at the network of the server with Wireshark and having incoming log messages with time stamps of the same msec - obviously the server has no time to send the acknowledge between incoming protocols. I.e. Sending #1 and # 2 in such a short sequence, obviously when sending #2 the counter for a missed message goes up to one. This is inherit by this system and is by design. Therefore, I'm going to implement a gap of at least a few msec between sending messages. Because the messages are all handled and forwarded in the application by signals / QtEvent queues, I dont have a solid idea so far how to do this. I may have to create a time gated sending queue before handing the messages over to the signal and the QtEvent queue.

@kshegunov said: the way the API is organized is a bit different from QTcpSocket You're right. I was also a little bit confused, when i used the QSerialBus module the first time (see my topic https://forum.qt.io/topic/65572/qmodbusmaster-example). Like i said, i think you can built your own class by inherit from QModbusDevice to have a synchronous API. The QSerialBus module is marked as technical preview in Qt 5.6, maybe they add some new functions in future releases similar to QTcpSocket like waitForConnected etc.

Hi, Thanks for your response. The whole body of code is proprietary so I'm not sure I can share it in a public forum. However I can make a note that it used to work fine a month ago and after that no changes occurred to this code and no qt libraries were replaced, so the issue is like to be caused by hardware malfunction. Thanks again ))

@mrjj Thanks :)

@mrjj Hi! I managed to make everything just as I wanted, everything is going fine. The code example you sent me really did the trick. Thanks a lot.

Hi, On a side note, there's no need to use fromStdString to initialize a QByteArray with a string.