Access to existing QML component from C++ - c++

Question

I am a newbie in QML, and cannot resolve a simple issue. I want to get access to the QML components from C++, but I cannot.
The pointer test is always 0. What can be the reason?
The code is the following:
main.cpp
int main(int argc, char *argv[])
{
QGuiApplication &app=reg6::Bonder::BonderGuiApplication::instance();
QQmlApplicationEngine engine;
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
QObject* test=engine.rootObjects().first()->findChild<QObject*> ("cameraArea");
test->setProperty("color","black");
return app.exec();
}
main.qml
import QtQuick 2.5
import QtQuick.Controls 1.4
import QtQuick.Dialogs 1.2
import QtQuick.Layouts 1.0
ApplicationWindow {
visible: true
width: 1800
height: 900
SplitView
{
anchors.fill: parent
orientation: Qt.Vertical
SplitView {
Layout.fillHeight: true
SplitView {
orientation: Qt.Vertical
width:400
Layout.minimumWidth: 400
Layout.maximumWidth: 500
Camera {
id: cameraArea
height: 400
Layout.maximumHeight: 400
Layout.minimumHeight: 300
}
List {
id: listArea
}
}
Bonder {
id: mainArea
Layout.fillWidth: true
}
Properties {
id: propertiesArea
Layout.minimumWidth: 300
Layout.maximumWidth: 400
}
}
Error {
id: errorArea
Layout.minimumHeight: 100
height: 200
}
}
}
Camera.qml
import QtQuick 2.5
Rectangle {
color: "lightblue"
}

Answer 1

You have to set the objectName property also of the QML component to get a valid pointer to your QObject because T QObject::findChild(const QString &name = QString(), Qt::FindChildOptions options = Qt::FindChildrenRecursively) const needs the objectName not the ID