C++与QML交互方法解析

// dataobject.h
class DataObject : public QObject
{
    Q_OBJECT
    Q_PROPERTY(QString name READ name WRITE setName NOTIFY nameChanged)
public:
    QString name() const { return m_name; }
    void setName(const QString &name) {
        if (m_name != name) {
            m_name = name;
            emit nameChanged();
        }
    }

signals:
    void nameChanged();

private:
    QString m_name;
};

// main.cpp
#include 
#include 

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    DataObject obj;
    obj.setName("Hello from C++");

    QQmlApplicationEngine engine;
    engine.rootContext()->setContextProperty("dataObj", &obj); // 关键：注册到上下文
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

    return app.exec();
}

// main.qml
Text {
    text: dataObj.name
}

// main.cpp 中注册类型
qmlRegisterType("MyModule", 1, 0, "DataObject");

// main.qml
import MyModule 1.0

DataObject {
    id: myData
    name: "Registered Type"
}

Text {
    text: myData.name
}

class Controller : public QObject
{
    Q_OBJECT
    Q_PROPERTY(int value READ value WRITE setValue NOTIFY valueChanged)
public:
    Q_INVOKABLE void reset() { setValue(0); }
    int value() const { return m_value; }
    void setValue(int v) {
        if (m_value != v) {
            m_value = v;
            emit valueChanged();
        }
    }

signals:
    void valueChanged();

private:
    int value = 0;
};

// 注册单例实例
auto *singleton = new SettingsManager(engine);
engine.rootContext()->setContextProperty("settings", singleton);
// 或使用 qmlRegisterSingletonType 实现延迟初始化

Text {
    text: settings.language
}