如何从 C++ 创建 Qml 组件？

Question

I tried to use QQmlComponent component(view.engine(), QUrl::fromLocalFile("MyItem.qml")); and then QOObject *object = component.create(); but it gives me Qml Component not ready. Further tried to connect the statusChanged signal to a slot function, but it doesnt seem to load the new qml components.

QQuickView view;
view.setSource(QUrl(QStringLiteral("qrc:/main.qml")));
QQmlComponent component(view.engine(), QUrl::fromLocalFile("MyItem.qml"));
QObject *object = component.create();
object->setParent(view.rootObject());
view.show()

Answer 1

If you're loading from a local file, then set the QQmlComponent to load synchronously by specifying it in the constructor:

QQmlComponent component(view.engine(),
                        QUrl::fromLocalFile("MyItem.qml"),
                        QQmlComponent::PreferSynchronous );

Answer 2

See Interacting with QML Objects from C++ .

Loading QML Objects from C++

A QML document can be loaded with QQmlComponent or QQuickView. QQmlComponent loads a QML document as a C++ object that can then be modified from C++ code. QQuickView also does this, but as QQuickView is a QWindow-derived class, the loaded object will also be rendered into a visual display; QQuickView is generally used to integrate a displayable QML object into an application's user interface.

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Also, more wide topic Integrating QML and C++ .