Qt中的事件

写一个 可以拖动的按钮

DraggablePushButton.h 头文件

#ifndef DRAGGABLEPUSHBUTTON_H
#define DRAGGABLEPUSHBUTTON_H#include <QPushButton>
#include <QMouseEvent>class DraggablePushButton : public QPushButton
{Q_OBJECTpublic:explicit DraggablePushButton(QWidget *parent = nullptr);protected:void mousePressEvent(QMouseEvent *event) override;void mouseMoveEvent(QMouseEvent *event) override;void mouseReleaseEvent(QMouseEvent *event) override;private:void showDialog();private:QPoint m_pressPosition;  // 鼠标按下位置int m_pressTime;         // 鼠标按下时间戳bool m_isDragging;       // 是否是拖动操作
};#endif // DRAGGABLEPUSHBUTTON_H

实现  DraggablePushButton.cpp

#include "DraggablePushButton.h"
#include <QMessageBox>
#include <QApplication>
#include <QDebug>DraggablePushButton::DraggablePushButton(QWidget *parent): QPushButton(parent), m_isDragging(false)
{
}void DraggablePushButton::mousePressEvent(QMouseEvent *event)
{if (event->button() == Qt::LeftButton) {m_pressPosition = event->pos();  // 记录鼠标按下的位置m_pressTime = event->timestamp();  // 记录鼠标按下的时间// 阻止默认的点击行为event->accept();}else {QPushButton::mousePressEvent(event);  // 其它鼠标按下事件处理}
}void DraggablePushButton::mouseMoveEvent(QMouseEvent *event)
{if (m_isDragging) {// 鼠标拖动时更新按钮位置QPoint delta = event->pos() - m_pressPosition;move(pos() + delta);  // 移动按钮event->accept();}else {// 判断是否是拖动操作int distance = (event->pos() - m_pressPosition).manhattanLength();if (distance > QApplication::startDragDistance()) {m_isDragging = true;  // 开始拖动}}
}void DraggablePushButton::mouseReleaseEvent(QMouseEvent *event)
{if (event->button() == Qt::LeftButton) {int releaseTime = event->timestamp();  // 记录释放的时间int timeDiff = releaseTime - m_pressTime;  // 计算按下和释放的时间差if (m_isDragging) {// 如果是拖动操作qDebug() << "Dragged";} else {// 如果按下和释放的时间差较短，并且鼠标位置没有变化，判定为双击if (timeDiff < QApplication::doubleClickInterval()) {qDebug() << "Double Clicked";showDialog();  // 弹出对话框} else {qDebug() << "Single Clicked";}}m_isDragging = false;  // 重置拖动标志event->accept();}else {QPushButton::mouseReleaseEvent(event);  // 其它鼠标释放事件处理}
}void DraggablePushButton::showDialog()
{// 弹出对话框QMessageBox::information(this, "Double Clicked", "You double-clicked the button!");
}