C++ 如何截获Qt快速qml事件？

我希望截获Qt Quick事件，例如，以便在它们到达当前目标（例如当前）之前对其进行处理，可以选择阻止事件在默认事件链中传播。这可以通过在QML代码中处理事件来实现吗？

这可以通过在顶层窗口中安装一个来实现。 通过使用QML单例保存对的引用，可以在QML源中的任何地方找到并访问顶级窗口（这并不简单：遵循或其他指南，并将引用保存在

组件中。
应用程序窗口的onCompleted
事件中）。事件过滤器可以安装一个C++ QML注册插件。
 C++事件过滤器插件是这样的：
#pragma once

#include <QQuickItem>

class QmlEventFilter : public QQuickItem
{
    Q_OBJECT
public:
    Q_PROPERTY(QObject * source READ getSource WRITE setSource)
    Q_PROPERTY(bool filterEnabled READ getFilterEnabled WRITE setFilterEnabled)

public:
    QmlEventFilter()
    {
        m_source = nullptr;
        m_filterEnabled = false;
    }

    ~QmlEventFilter()
    {
        if (m_source != nullptr)
            m_source->removeEventFilter(this);
    }

    void setSource(QObject *source)
    {
        source->installEventFilter(this);
        m_source = source;
    };

    QObject * getSource() { return m_source; }
    void setFilterEnabled(bool value) { m_filterEnabled = value; }
    bool getFilterEnabled() { return m_filterEnabled; }

private:

    void keyPressEvent(QKeyEvent *event) override
    {
        // This is actually called when the QML event handler hasn't accepted the event
        m_qmlAccepted = false;

        // Ensure the event won't be propagated further
        event->setAccepted(true);
    }

    void keyReleaseEvent(QKeyEvent *event) override
    {
        // This is actually called when the QML event handler hasn't accepted the event
        m_qmlAccepted = false;

        // Ensure the event won't be propagated further
        event->setAccepted(true);
    }

    bool eventFilter(QObject *obj, QEvent *event) override
    {
        if (!m_filterEnabled)
            return false;

        bool ret = false;
        switch (event->type())
        {
        case QEvent::KeyPress:
        case QEvent::KeyRelease:
            m_qmlAccepted = true;
            QCoreApplication::sendEvent(this, event);
            ret = m_qmlAccepted;
            break;
        }
        return ret;
    }

private:
    QObject *m_source;
    bool m_filterEnabled;
    bool m_qmlAccepted;
};

    qmlRegisterType<QmlEventFilter>("MyPlugins", 1, 0, "EventFilter");

import MyPlugins 1.0

[...]

EventFilter
{
    id: filter
    filterEnabled: true // It can also be enabled on demand in other events
    Keys.onPressed:
    {
        // Accepting the event won't propagate the event
        // with the default event chain
        event.accepted = true
        console.log("onPressed")
    }
}

Component.onCompleted:
{
    // Singleton.window is the top level QML ApplicationWindow
    filter.source = Singleton.window
}