qml Integration with C++ Creating a QtQuick view from C++


Example

It is possible to create a QtQuick view directly from C++ and to expose to QML C++ defined properties. In the code below the C++ program creates a QtQuick view and exposes to QML the height and width of the view as properties.

main.cpp

#include <QApplication>
#include <QQmlContext>
#include <QQuickView>

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

    // Creating the view and manually setting the QML file it should display
    QQuickView view;
    view.setSource(QStringLiteral("main.qml"));
    
    // Retrieving the QML context. This context allows us to expose data to the QML components
    QQmlContext* rootContext = view.rootContext();

    // Creating 2 new properties: the width and height of the view
    rootContext->setContextProperty("WINDOW_WIDTH", 640);
    rootContext->setContextProperty("WINDOW_HEIGHT", 360);

    // Let's display the view
    view.show();

    return app.exec();
}

main.qml

import QtQuick 2.0

Rectangle {
    // We can now access the properties we defined from C++ from the whole QML file
    width: WINDOW_WIDTH
    height: WINDOW_HEIGHT

    Text {
        text: qsTr("Hello World")
        anchors.centerIn: parent
    }
}