How to call message dialog from qt c++ ?

Ahti

What is the proper way to call a message dialog from c++ ? here is my code so far:

main.qml:

Window {
    visible: true
    minimumWidth: 350
    minimumHeight: 500 

    MessageDialog {
        id: err_msg
        title: "Error"
    }
}

example.cpp:

void Example::some_func(){
        // call message dialog here with error message.
}

Thanks

SGaist

Hi,

Did you already read the C++ QML Integration guide ?

Ahti

@SGaist yes in fact Example is already registered to QML but I don't understand how would I show message dialog once I encounter an error in c++.

ODБOï

@Ahti hi
use signal /slot mechanism

Window {
    visible: true
    minimumWidth: 350
    minimumHeight: 500 

  Example{
    onErrorSignal : err_msg.show()
  }
 

    MessageDialog {
        id: err_msg
        title: "Error"
    }
}
//example.cpp:

void Example::some_func(){
        // call message dialog here with error message., emit a signal
    emit errorSignal();
       
}

Ahti

@LeLev This doesn't work:

 Example{
    onErrorSignal : err_msg.show()
  }

mainly because I have set Example as property with rootContext() like this:

main.cpp:

Example e;    
engine.rootContext()->setContextProperty("example", &e);

ODБOï

@Ahti you can une QML Connections type like this

Connections {
        target: example
         onErrorSignal : err_msg.show()
    }

https://doc.qt.io/qt-5/qtqml-cppintegration-overview.html

Pradeep P N

Hi @Ahti

You can also expose the function as Q_INVOKABLE or use it as public slots: with return type as bool.
And use that function in QML .

public:
  Q_INVOKABLE bool some_func();

// OR

public slots:
  bool some_func();

    MessageDialog {
        id: err_msg

        title: "Error"
        visible: example.some_func();
    }

Hope it was of help.
All the best.

ODБOï

@Pradeep-P-N hi, you should tag the OP, not me

Pradeep P N

@LeLev the reply was from Mobile, so it got missed.