• 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;
    }
}