qt 重写eventfilter

Sure, I can help you with that!

To override the `eventFilter()` function in Qt, you need to do the following:

1. Create a new class that inherits `QObject`, for example:

class MyEventFilter : public QObject
{
public:
    explicit MyEventFilter(QObject *parent = nullptr);

protected:
    bool eventFilter(QObject *obj, QEvent *event) override;
};

2. Implement the `eventFilter()` function in your new class:

bool MyEventFilter::eventFilter(QObject *obj, QEvent *event)
{
    if (event->type() == QEvent::KeyPress) {
        QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
        qDebug() << "Key press:" << keyEvent->key();
        return true; // to stop further processing of the event
    }
    // process other events normally
    return QObject::eventFilter(obj, event);
}

3. Install the event filter on the object you want to monitor for events, for example:

MyEventFilter *eventFilter = new MyEventFilter(this);
QLineEdit *lineEdit = new QLineEdit(this);
lineEdit->installEventFilter(eventFilter);

Now, when you type in the `QLineEdit`, the `eventFilter()` function will be called for each event, and you can handle the events as needed.

I hope this helps! Let me know if you have any further questions.