[SOLVED] How to call C++ class or function on QML

[A Former User]

Hello everybody ;

I want to call C++ class or function into my QML design ... How can I do it ? :) please show me with a example of method for Qt 5.2 or later.

For example this is my class and function in C++ file.

@
class MyClass
{
void MyFunction()
{

qDebug() << "This is C++ Code ! but GUI designed by QMl technology";

}

};
@

and QML Button code

@
Button {
text: qsTr("Hello World")
anchors.centerIn: parent

}

@

[qxoz]

Have you seen this "doc ( Integrating QML and C++ ) ":https://qt-project.org/doc/qt-5/qtqml-cppintegration-topic.html ?

[A Former User]

Yes , But i want example with source code for QML or HTML5 design.

[quote author="qxoz" date="1399267156"]Have you seen this "doc ( Integrating QML and C++ ) ":https://qt-project.org/doc/qt-5/qtqml-cppintegration-topic.html ?[/quote]

[JKSH]

Example source code at https://qt-project.org/doc/qt-5/qtqml-cppintegration-contextproperties.html

Note that you can only objects derived from QObject can be accessed directly from QML.

[A Former User]

[quote author="JKSH" date="1399275337"]Example source code at https://qt-project.org/doc/qt-5/qtqml-cppintegration-contextproperties.html

Note that you can only objects derived from QObject can be accessed directly from QML.[/quote]

I Check this but show this error :

@
/home/kambiz/Documents/Projects/untitled6/main.cpp:8: error: undefined reference to `vtable for ApplicationData'
@

Unfortunately I don't have experience with QML :(

[pmoglaikar]

Hi Kamb!z,

Here is the working example I have complied and run it ....... !

// ---- sample_ttr.pro ---

#-------------------------------------------------

Project created by QtCreator 2014-05-05T18:05:02

#-------------------------------------------------

QT += core gui
QT += quick

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = sample_ttr
TEMPLATE = app

SOURCES += main.cpp

HEADERS +=
ApplicationData.h

FORMS +=

OTHER_FILES +=
MyItem.qml

---

// ---- main.cpp ---

#include <QApplication>
#include <QtQuick/QQuickView>
#include <QQmlContext>
#include "ApplicationData.h"

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QQuickView view;

ApplicationData data;
view.rootContext()->setContextProperty("ApplicationData", &data);
view.setSource(QUrl::fromLocalFile("MyItem.qml"));
view.show();


return a.exec();

}

---

// --- ApplicationData.h ---

#ifndef APPLICATIONDATA_H
#define APPLICATIONDATA_H
#include <QObject>
#include <QDateTime>
class ApplicationData : public QObject
{
Q_OBJECT
public:
Q_INVOKABLE QDateTime getCurrentDateTime() const {
return QDateTime::currentDateTime();
}
};
#endif // APPLICATIONDATA_H

---

// ---- MyItem.qml ---

// MyItem.qml
import QtQuick 2.0

Text { text: applicationData.getCurrentDateTime() }

---

Thanks
Prashant

[A Former User]

[quote author="Prashant Moglaikar" date="1399294151"]Hi Kamb!z,

Here is the working example I have complied and run it ....... !

// ---- sample_ttr.pro ---

#-------------------------------------------------

Project created by QtCreator 2014-05-05T18:05:02

#-------------------------------------------------

QT += core gui
QT += quick

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = sample_ttr
TEMPLATE = app

SOURCES += main.cpp

HEADERS +=
ApplicationData.h

FORMS +=

OTHER_FILES +=
MyItem.qml

---

// ---- main.cpp ---

#include <QApplication>
#include <QtQuick/QQuickView>
#include <QQmlContext>
#include "ApplicationData.h"

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QQuickView view;

ApplicationData data;
view.rootContext()->setContextProperty("ApplicationData", &data);
view.setSource(QUrl::fromLocalFile("MyItem.qml"));
view.show();


return a.exec();

}

---

// --- ApplicationData.h ---

#ifndef APPLICATIONDATA_H
#define APPLICATIONDATA_H
#include <QObject>
#include <QDateTime>
class ApplicationData : public QObject
{
Q_OBJECT
public:
Q_INVOKABLE QDateTime getCurrentDateTime() const {
return QDateTime::currentDateTime();
}
};
#endif // APPLICATIONDATA_H

---

// ---- MyItem.qml ---

// MyItem.qml
import QtQuick 2.0

Text { text: applicationData.getCurrentDateTime() }

---

Thanks
Prashant[/quote]

Hi , and Very very thank you Prashant!

[pmoglaikar]

Hi Kamb!z,

Your Welcome to Qt's cross platform world !!!

Thanks
Prashant Moglaikar