将 C++ 信号连接到 QML 插槽

Question

I'm trying to connect a C++ signal with a QML slot.

The C++ signal is called userRegistered() and the QML slot is called userRegisteredQML() .

In the C++ file, I have the following:

QQuickView view(QUrl::fromLocalFile("interface.qml"));

QObject *topLevel = view.rootContext();

connect(myClass, SIGNAL(userRegistered()), topLevel, SLOT(userRegisteredQML()));

And in the interface.qml , I have the slot userRegisteredQML :

function userRegisteredQML(){
    console.log("this is a test!");
}

The problem is that it does not show "this a test!". Therefore, I wanted to ask you if this is the proper way to connect a C++ signal to a QML slot.

Answer 1

QML js functions are not slots.
You should just create the signal in C++ and in QML you handle it with on.
This is Also where exactly that signal exists.
If it is a QML_ELEMENT you would handle it inside the component instantiation in QML.

SomeTypeFromC++{
    onUserRegistered: {do_somthing()}
}

If it is in an engine rootContextProperty You can use Connections QML type:

Connections {
    target: appCore // The name of the context property
    onUserRegistered: {do_somthing()}
}

Answer 2

Expose your object to QML in C++:

topLevel->setContextProperty("MyClass", myClass);

In QML, you can use Connections:

Connections {
    target: MyClass 
    userRegistered: {
        // do something with it here
    }
}