事件过滤器

每个派生自QObject 的对象都可以 调用该函数
QObject::installEventFilter(QObject *filterObj) 去过滤自己所能处理的事件

参数 filterObj

该参数为实现 eventFilter(QObject *obj, QEvent *event) 过滤函数的 类对象

例如过滤器类

class KeyPressEater : public QObject

{

Q_OBJECT

protected:

bool eventFilter(QObject *obj, QEvent *event);

};

bool KeyPressEater::eventFilter(QObject *obj, QEvent *event)

{

if (event->type() == QEvent::KeyPress) {

QKeyEvent *keyEvent = static_cast(event);

qDebug("Ate key press %d", keyEvent->key());

// true 相当于 accept() false 相当于 ignore()

return true;

} else {

// standard event processing

return QObject::eventFilter(obj, event);

}

}

安装过滤器

keyPressEater = new KeyPressEater();

pushButton = new QPushButton(父窗口);

listView = new QListView(父窗口);

pushButton->installEventFilter(keyPressEater);

listView->installEventFilter(keyPressEater);