Delete QML Objects from C++

[Jens van koolwijk]

Hello i know how to create and update property's on qml from c++. But how do i delete/destroy the object from the qmlApplicationEngine.

//Creating

    QQmlApplicationEngine *qmlApplicationEngine = new QQmlApplicationEngine();
    qmlApplicationEngine->load(QUrl(QStringLiteral("qrc:/main.qml")));

    QQmlComponent component(qmlApplicationEngine, QUrl(QStringLiteral("qrc:/Video.qml")));
    QQuickItem *qQuickItem = qobject_cast<QQuickItem*>(component.create());
    QQmlEngine::setObjectOwnership(qQuickItem, QQmlEngine::CppOwnership);
    qQuickItem->setParent(qmlApplicationEngine);
    qQuickItem->setParentItem(qobject_cast<QQuickWindow*>(qmlApplicationEngine->rootObjects().at(0))->contentItem());

[A Former User]

@Jens-van-koolwijk Hi, welcome to the Qt forum! You use QQmlEngine::CppOwnership, so the QML engine knows that it's your responsibility to delete the object. Just call delete qQuickItem; or qQuickItem->deleteLater();.

[Jens van koolwijk]

@Wieland Hello , thank you for the quick response. Perhaps I have not sufficiently explained my question. If for example, I 've created a video player in the QML file that I play . If I then remove the object while it is playing the audio stays but the visual gets black. If I stop the video first and then remove it seems that not everything cleared according to the QML debugger . what is the correct way . Do i need to make Deconstructor function in QML.

[A Former User]

Hmm.. does this happen when you use deleteLater()? Because it shouldn't and if so then it's a bug.

[jeremy_k]

Is creating the object from QML instead of C++ an option? As noted, deleting the C++ object while the QML engine is running may have unexpected results.

If the lifetime of the object needs to be shorter than the lifetime of the parent item, http://doc.qt.io/qt-5/qtqml-javascript-dynamicobjectcreation.html covers several options.

[Jens van koolwijk]

@jeremy_k
Thank you.I will try it out