Connect QML signal to CPP slot, or method [SOLVED]

Neon_Burg

I want to establish a connection between CPP class methods and QML file, but i always get a strange errors, that i cant understand... Help me somebody !

main.cpp

@#include <QApplication>
#include <QQmlApplicationEngine>
#include <QtDeclarative/QDeclarativeView>
#include <QtDeclarative/QDeclarativeContext>
#include <QGraphicsObject>
#include <QDebug>

class MyClass : public QObject
{
Q_OBJECT
public slots:
void cppSlot(const QString &msg) {
qDebug() << "Called the C++ slot with message:" << msg;
}
};

int main(int argc, char *argv[])
{
QApplication app(argc, argv);

//QQmlApplicationEngine engine;
//engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

QDeclarativeView view(QUrl(QStringLiteral("main.qml")));
QObject *item = view.rootObject();

MyClass myClass;
QObject::connect(item, SIGNAL(qmlSignal(QString)),
                      &myClass, SLOT(cppSlot(QString)));
view.show();

return app.exec&#40;&#41;;

}@

main.qml

@import QtQuick 2.3
import QtQuick.Controls 1.2

ApplicationWindow {
id: item
visible: true
width: 640
height: 480
color: "#ffffff"
title: qsTr("Hello World")
signal qmlSignal(string msg)

Button {
    id: button1
    x: 27
    y: 37
    width: 97
    height: 61
    text: qsTr("Button")
    onClicked: item.cppSlot("Hello C++ from QML !!!")
}

}
@

Trying to run this app, i get an errors like this:

C:\Qt\PROJECTS\QML_with_C\main.cpp:24: error: undefined reference to `_imp___ZN16QDeclarativeViewC1ERK4QUrlP7QWidget'

and this

C:\Qt\PROJECTS\QML_with_C\main.cpp:8: error: undefined reference to `vtable for MyClass'

Rolias

It looks like you're just experimenting and learning but I thought I would point out in case you don't know that: QML is automatically aware of Qt C++ slots so you could eliminate the QML signal, the QObject::connect statement (not to mention the curly braces in your onclicked handler). Your QML would just call the slot directly:

@onClicked: myObj.cppSlot("Your message here.")@

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Connect QML signal to CPP slot, or method [SOLVED]