General and Desktop

Then you are going to have to tell us in great detail exactly what you are doing. You say that this all started when you removed a blank. From where ? The source code ? the pro file ? a .pri or .prf file ? For instance I don't understand what you mean by: "the test project can run well, but I overwrite the test project's pro and source file to my project, " So tell us what exactly happens in detailed step, like: Step 1. I open my project in QtCreator Version (xxx.yyy) Step 2. Project | Clean Step 3. Project | Run QMake Step 4. Project | Rebuild Step 5. Project Execute - Ok < Now I overwrite pro file ???> Step 6. File | Open Project ???? .... Step N: Project | Execute - Seg fault

@kain said in Callback-Slot mechanism: This looks to me like some kind of workaround because I will probably need a several RequestCallback-objects. Or are there any better ideas? This makes me think of some sort of Notification Center. Some objects emit a notificarion and other objects register themselves to receive that notification. For example, with the preferences Dialog, when the user click OK, the prefDialog emits a PrefsDidChanged notification. Each windows or views that need to be informed of any changes register itself to receive that notification. I'm using custom events to emit this notification. EventCenter().addObserver(this, Event_AppPrefsDidChange); This line register 'this' to receive the AppPrefsDidChange notif. The notificationCenter post the event: QApplication::postEvent(o.observer,new CustomEvent(eventType,sender)); And in the receiver: void TextDocWindow::customEvent(QEvent* event) { CustomEvent* ev =static_cast<CustomEvent*>(event); switch (ev->subType()) { case Event_AppPrefsDidChange: Log("Prefs changed"); setupFromPrefs(); break; } } Here it's a text editor, the prefs changes can be color of text, size of font. etc. In the custom event object, you can pass any information you need to the receiver: class CustomEvent : public QEvent { public: CustomEvent(uint type,QObject* sender); virtual ~CustomEvent() { } QObject* sender() { return oSender; } uint subType() { return vSubType; } private: QObject* oSender; uint vSubType; }; It's possible to receive a type of notification from a particular object only. void addObserver(QObject *observer, uint eventType, QObject* sender=0); Here it is the sender extra parameter. Voilà, just an idea, hope it can help you.

Thanks! That helped big time!

I might be missing something but this looks like a bug in your code that can't manage the sizing once the scrollbars are shown. Doesn't sound like a problem in Qt

@TheEnigmist said in Enabling exceptions to Qt project in Visual Studio 2017: Yes, I found out that Qt container suppose an index is alredy checked before accessing a list Not really: http://doc.qt.io/qt-5/qlist.html#value-1

Hi all, I was setting Driver name in wrong way. I've changed "SQL SERVER" to "ODBC Driver 17 for SQL Server" mDatabase.setDatabaseName("DRIVER={ODBC Driver 17 for SQL Server};" "Server=XXXX;" "Database=XXXXX;" "Uid=XXX;" "Port=1433;" "Pwd=XXXX;" "WSID=."); Works like a charm. Thanks all

Thank you for your answer. What if I want to call this function asynchronously? I tried to call this function asynchronously in C++, but it failed. Cheers

qt5_add_resources is obsolete. if you set(CMAKE_AUTORCC ON) just add your .qrc files as they were .cpp to add_library/add_executable moc needs the headers, make sure CMake can see them, usually you can use set(CMAKE_INCLUDE_CURRENT_DIR ON)

@mic19 It should be nmake.exe not make when using VS

ah.. Thank you @J-Hilk

@JonB it didn't work for me :( EDIT: i used isRowSelected() and that worked

@mrjj thanks for ur reply & thank u all ,,, i changed two lines of code,,,now whatever i text ,,that is showing first ,,,this is i wanted anyway thanku all for ur reply ,,i got output wat i wanted! Mainwindow.cpp #include "mainwindow.h" #include "ui_mainwindow.h" MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { ui->setupUi(this); } MainWindow::~MainWindow() { delete ui; } void MainWindow::on_add_clicked() { QString text=ui->lineEdit->text(); QListWidgetItem * item = new QListWidgetItem(text); item->setFlags(item->flags() | Qt::ItemIsEditable); int row = ui->listWidget->row(ui->listWidget->currentItem()); ui->listWidget->insertItem(row, item); ui->lineEdit->clear(); } void MainWindow::on_delete_2_clicked() { delete ui->listWidget->currentItem(); } Ui Page [image: a6cfc9ed-cfe6-4fac-9166-877158759726.PNG]

@bladekel I found it.... Here is the new syntax... connect(&arduino,&QIODevice::readyRead,this,&MainWindow::serial_received);

@jsulm your method works, thanks.

I mean what backend are you using ? If not QWS, do you have an Xorg server running on your device ?

Can you provide a minimal compilable example that shows the behaviour ?

Hi, From the looks of it, you would have to rebuild Qt yourself.