使用EventFilter进行事件过滤

来源：互联网发布：vc map数据如何拷贝编辑：程序博客网时间：2024/06/06 18:13

1.效果图
这里写图片描述

2.源码
eventfilter.h

#ifndef EVENTFILTER_H#define EVENTFILTER_H#include <QDialog>#include <QLabel>#include <QImage>#include <QEvent>class EventFilter : public QDialog{    Q_OBJECTpublic:    EventFilter(QWidget *parent = 0,Qt::WindowFlags f=0);    ~EventFilter();public slots:    bool eventFilter(QObject *, QEvent *);//事件过滤private:    QLabel *label1;    QLabel *label2;    QLabel *label3;    QLabel *stateLabel;    QImage Image1;    QImage Image2;    QImage Image3;};#endif // EVENTFILTER_H

eventfilter.cpp

#include "eventfilter.h"#include <QHBoxLayout>#include <QVBoxLayout>#include <QMouseEvent>#include <QMatrix>EventFilter::EventFilter(QWidget *parent,Qt::WindowFlags f)    : QDialog(parent,f){    setWindowTitle(tr("事件过滤"));    label1 = new QLabel;    Image1.load("../image/1.png");    label1->setAlignment(Qt::AlignHCenter|Qt::AlignVCenter);    label1->setPixmap(QPixmap::fromImage(Image1));    label2 = new QLabel;    Image2.load("../image/2.png");    label2->setAlignment(Qt::AlignHCenter|Qt::AlignVCenter);    label2->setPixmap(QPixmap::fromImage(Image2));    label3 = new QLabel;    Image3.load("../image/3.png");    label3->setAlignment(Qt::AlignHCenter|Qt::AlignVCenter);    label3->setPixmap(QPixmap::fromImage(Image3));    //界面布局    stateLabel = new QLabel(tr("鼠标按下标志"));    stateLabel->setAlignment(Qt::AlignHCenter);    QHBoxLayout *layout=new QHBoxLayout;    layout->addWidget(label1);    layout->addWidget(label2);    layout->addWidget(label3);    QVBoxLayout *mainLayout = new QVBoxLayout(this);    mainLayout->addLayout(layout);    mainLayout->addWidget(stateLabel);    //安装事件过滤    label1->installEventFilter(this);    label2->installEventFilter(this);    label3->installEventFilter(this);}EventFilter::~EventFilter(){}bool EventFilter::eventFilter(QObject *watched, QEvent *event){    if(watched==label1)    {        if(event->type()==QEvent::MouseButtonPress)        {            QMouseEvent *mouseEvent=(QMouseEvent *)event;            if(mouseEvent->buttons()&Qt::LeftButton)            {                stateLabel->setText(tr("左键按下左边图片"));            }            else if(mouseEvent->buttons()&Qt::MidButton)            {                stateLabel->setText(tr("中键按下左边图片"));            }            else if(mouseEvent->buttons()&Qt::RightButton)            {                stateLabel->setText(tr("右键按下左边图片"));            }            QMatrix matrix;            matrix.scale(1.8,1.8);            QImage tmpImg=Image1.transformed(matrix);            label1->setPixmap(QPixmap::fromImage(tmpImg));        }        if(event->type()==QEvent::MouseButtonRelease)        {            stateLabel->setText(tr("鼠标释放左边图片"));            label1->setPixmap(QPixmap::fromImage(Image1));        }    }    else if(watched==label2)    {        if(event->type()==QEvent::MouseButtonPress)        {            QMouseEvent *mouseEvent=(QMouseEvent *)event;            if(mouseEvent->buttons()&Qt::LeftButton)            {                stateLabel->setText(tr("左键按下中间图片"));            }            else if(mouseEvent->buttons()&Qt::MidButton)            {                stateLabel->setText(tr("中键按下中间图片"));            }            else if(mouseEvent->buttons()&Qt::RightButton)            {                stateLabel->setText(tr("右键按下中间图片"));            }            QMatrix matrix;            matrix.scale(1.8,1.8);            QImage tmpImg=Image2.transformed(matrix);            label2->setPixmap(QPixmap::fromImage(tmpImg));        }        if(event->type()==QEvent::MouseButtonRelease)        {            stateLabel->setText(tr("鼠标释放中间图片"));            label2->setPixmap(QPixmap::fromImage(Image2));        }    }    else if(watched==label3)    {        if(event->type()==QEvent::MouseButtonPress)        {            QMouseEvent *mouseEvent=(QMouseEvent *)event;            if(mouseEvent->buttons()&Qt::LeftButton)            {                stateLabel->setText(tr("左键按下右边图片"));            }            else if(mouseEvent->buttons()&Qt::MidButton)            {                stateLabel->setText(tr("中键按下右边图片"));            }            else if(mouseEvent->buttons()&Qt::RightButton)            {                stateLabel->setText(tr("右键按下右边图片"));            }            QMatrix matrix;            matrix.scale(1.8,1.8);            QImage tmpImg=Image3.transformed(matrix);            label3->setPixmap(QPixmap::fromImage(tmpImg));        }        if(event->type()==QEvent::MouseButtonRelease)        {            stateLabel->setText(tr("鼠标释放右边图片"));            label3->setPixmap(QPixmap::fromImage(Image3));        }    }    return QDialog::eventFilter(watched,event);}

阅读全文

0 0