CODEWITHSUNDEEP
c++qtqml
Parthi
Parthi

Reputation: 1

How to access QVariantMap value in QML when I pass QVariantMap from cpp through QPROPERTY

I want to send QVariantMap to QML from cpp using QPROPERTY. I am able to send it. But I am not able to access the QVariantMap key or Value in QML. I am not getting the way to access using object of cpp class. Also I am trying to set model for listview using this QVariantMap. I am able to do with QVariantList and I can access data through "modelData".

When I try to access the QVariantMap data through "modelData", I am not getting anything.

Upvotes: 0

Views: 4959

Answers (1)

epsilon
epsilon

Reputation: 2969

As @ManuelH commented, the relevant documentation is located here

Here is how you expose your QVariantMap instance to your QML:

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QVariantMap>
#include <QQmlContext>

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

    QGuiApplication app(argc, argv);

    QVariantList bazList = { "hello", "world!" };

    QVariantMap variantMap;
    variantMap["foo"] = "bar";
    variantMap["num"] = 42;
    variantMap["baz"] = bazList;

    QQmlApplicationEngine engine;
    // Exposing the QVariantMap in the QML engine root context
    engine.rootContext()->setContextProperty("variantMap", variantMap);

    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    if (engine.rootObjects().isEmpty())
        return -1;

    return app.exec();
}

Here is how you access your QVariantMap properties in your QML. As the documentation states, your map is converted as a Javascript Object. You can therefore the keys in your map as you would to access your Object properties:

import QtQuick 2.9
import QtQuick.Window 2.2

Window {
    visible: true
    width: 640
    height: 480


    Column {
        width: 640
        anchors.centerIn: parent

        Text { text: "varianMap is of type: " + typeof(variantMap) }
        Text { text: variantMap["foo"] }
        Text { text: variantMap.foo }
        Text { text: "Foo is of type: " + typeof(variantMap.foo) }
        Text { text: variantMap["num"] }
        Text { text: variantMap.num }
        Text { text: "Num is of type: " + typeof(variantMap.num) }

        // Accessing nested QVarianList by index
        Text { text: variantMap.baz[0] }
        Text { text: variantMap.baz[1] }

        Repeater {
            model: variantMap.baz // Using list as model

            Text {
                text: modelData // Using list value directly
            }

            Text {
                text: variantMap.baz[index] // Using list value by index
            }
        }
    }
}

Upvotes: 0

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