QT eventFilter mouseEvent->pos().x() 始終為零但 mouseEvent->pos().y() 工作正常

Question

mouseEvent->pos().x() 總是返回 0。 mouseEvent->pos().y() 在鼠標移動時更新

bool Module3::eventFilter(QObject *obj, QEvent *event) { 

      QMouseEvent *mouseEvent = static_cast(event);

      if(obj ==scene && event->type() == QEvent::GraphicsSceneMouseMove){

          QToolTip::showText(mouseEvent->pos(),QString::number(mouseEvent->pos().x()) + 
           ", "  + QString::number( mouseEvent->pos().y()));
       }

       return false;
}

Answer 1

你有未定義的行為。 如果event->type()是QEvent::GraphicsSceneMouseMove那么真正的事件類型是QGraphicsSceneMouseEvent*而不是QMouseEvent* 。

嘗試...

if (obj == scene && event->type() == QEvent::GraphicsSceneMouseMove) {
    if (auto *mouseEvent = dynamic_cast<QGraphicsSceneMouseEvent *>(event)) {
        QToolTip::showText(mouseEvent->scenePos().toPoint(),QString::number(mouseEvent->pos().x()) + 
            ", "  + QString::number( mouseEvent->pos().y()));
    }
}
return false;