Display Data from C++ to QML

[Binary01]

Hi EveryOne,

I have a C++ class that does some operations
The method : getDataFromServer() exports some Data from server, it works well
for (int i = 0; i < projects.size(); ++i)
{
qDebug() << "result : " << projects[i];
}

I want to display data in Listview QML

QML code
Rectangle
{
Component.onCompleted: {
ClassTest.getDataFromServer();
}

ClassTest{
id: classTest
}

Item {
width: 800
height: 600

ListView {
id: listView
anchors.left: parent.left
anchors.top: parent.top
anchors.bottom: parent.bottom
width: 0.25 * parent.width

focus: true
model: myModel
delegate: Item {

width: parent.width
height: 22

Text {
anchors.centerIn: parent
text: "data"
}

MouseArea {
anchors.fill: parent
onClicked: {
console.log(model.index)
}

}
}
}
}


getDataFromServer() code


...
// getData OK
for (int i = 0; i < projects.size(); ++i)
{
qDebug() << "result : " << projects[i];
}
QQuickView *view= new QQuickView;
QQmlContext *c = view->engine()->rootContext();
c->setContextProperty("myModel", QVariant::fromValue(projects));

Any help plz ;)

Cheers,

[anda_skoa]

Your getDataFromServer() creates a new view?

Cheers,
_

[Binary01]

The object is to display Data in QML

I created a new QML file code above , I would like to communicate C++ class and This QML file, so I tried to use :

QQuickView *view= new QQuickView;
QQmlContext *c = view->engine()->rootContext();
c->setContextProperty("myModel", QVariant::fromValue(projects));

Is this an other way simple to do that ??

[anda_skoa]

The object is to display Data in QML

If you create another view, it is another view.
In C++ two instance of a class are two different objects, with their owns state/data.



Is this an other way simple to do that ??
Either a property on an object exposed to QML or a model exposed to QML.
What's the element type of "projects"?

Cheers,
_

[Binary01]

projects is a QStringList : QStringList projects

Yeah I used a model exposed to QML : myModel

I tried to use the example : http://doc.qt.io/qt-5/qtquick-modelviewsdata-cppmodels.html

Cheers,

[anda_skoa]

projects is a QStringList : QStringList projects

Ah, good, easy :)



Yeah I used a model exposed to QML : myModel

Currently you are not, your non-working code exports the QStringList as a context property.

I assume "ClassTest" is a custom C++ type that you have registered with the QML type system?

Just add a QStringList property to it and bind the ListView's model to that instead of myModel.


ClassTest {
id: classTest
}

ListView {
model: classTest.projects // assuming you give your property the name "projects"
}


Cheers,
_

[Binary01]

Yeah, "ClassTest" is a custom C++ type registered with the QML type system

Is it necessary to add a new property ??

In ClassTest, I added projects

Q_PROPERTY(QStringList projects READ projects)

In QML

ListView {
model: classTest.projects
}

In C++

// getDataFromServer() == Get data From server
for (int i = 0; i < projects.size(); ++i)
{
qDebug() << "result : " << projects[i];
}

QQuickView *view= new QQuickView;
QQmlContext *ctxt = view->engine()->rootContext();
ctxt->setContextProperty("myModel", QVariant::fromValue(projects));


Still not work
C++ code should remain as such it is ??

Cheers,

[anda_skoa]

Yeah, "ClassTest" is a custom C++ type registered with the QML type system

Great, that makes everything easy.



Is it necessary to add a new property ??

That's the easiest way.
Do you need a more complicated approach?



In ClassTest, I added projects

Q_PROPERTY(QStringList projects READ projects)

Needs a NOTIFY signal, since the value is changing after object creation.



In QML

ListView {
model: classTest.projects
}

Exactly.



In C++

// getDataFromServer() == Get data From server
for (int i = 0; i < projects.size(); ++i)
{
qDebug() << "result : " << projects[i];
}

QQuickView *view= new QQuickView;
QQmlContext *ctxt = view->engine()->rootContext();
ctxt->setContextProperty("myModel", QVariant::fromValue(projects));


We've already determined that this is very wrong, no?

Once the value of the property has changed, you emit the change notifcation signal.

Cheers,
_