24 鼠标常用事件

• 鼠标进入：enterEvent
• 鼠标离开：leaveEvent
• 鼠标按下：mousePressEvent
• 鼠标释放：mouseRelaseEvent
• 鼠标移动：mouseMoveEvent

 提升为自定义控件MyLabel

代码：

//mylabel.h
#ifndef MYLABEL_H
#define MYLABEL_H#include <QLabel>class MyLabel : public QLabel
{Q_OBJECT
public:explicit MyLabel(QWidget *parent = 0);//鼠标进入void enterEvent(QEvent *);//鼠标离开void leaveEvent(QEvent *);//鼠标按下void mousePressEvent(QMouseEvent *ev);//鼠标释放void mouseReleaseEvent(QMouseEvent *ev);//鼠标移动void mouseMoveEvent(QMouseEvent *ev);signals:public slots:
};#endif // MYLABEL_H

//mylabel.cpp
#include "mylabel.h"
#include "QDebug"
#include "QMouseEvent"MyLabel::MyLabel(QWidget *parent) : QLabel(parent)
{//设置鼠标追踪
//    this->setMouseTracking(true);
}//鼠标进入
void MyLabel::enterEvent(QEvent *){qDebug()<<"鼠标进入";
}//鼠标离开
void MyLabel::leaveEvent(QEvent *){qDebug()<<"鼠标离开";
}//鼠标按下
void MyLabel::mousePressEvent(QMouseEvent *ev){//如果是鼠标左键按下，才打印信息if(ev->button() == Qt::LeftButton){//字符串格式化QString str = QString("鼠标按下: x= %1 , y= %2").arg(ev->x()).arg(ev->y());qDebug()<<str;}
}//鼠标释放
void MyLabel::mouseReleaseEvent(QMouseEvent *ev){if(ev->button() == Qt::LeftButton){QString str = QString("鼠标释放: x= %1 , y= %2").arg(ev->x()).arg(ev->y());qDebug()<<str;}
}//鼠标移动
void MyLabel::mouseMoveEvent(QMouseEvent *ev){//按位与运算&if(ev->buttons() & Qt::LeftButton){QString str = QString("鼠标移动: x= %1 , y= %2").arg(ev->x()).arg(ev->y());qDebug()<<str;}
}