Qt事件

傷城~ 2021-11-23 01:42 628阅读 0赞

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzMTM0MjA4NDc3Ng_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzMTM0MjA4NDc3Ng_size_16_color_FFFFFF_t_70 1][]

### 1) 项目（右键）---> 添加新文件 ---> C++ ---> C++ Class---> Choose ###

![20190725150214335.png][]

#ifndef MYLABEL_H
    #define MYLABEL_H
    
    #include <QLabel>
    
    class MyLabel : public QLabel
    {
        Q_OBJECT
    public:
        explicit MyLabel(QWidget *parent = 0);
    
    
    protected:
       //鼠标点击事件
       void mousePressEvent(QMouseEvent *ev);
       //鼠标释放事件
       void mouseReleaseEvent(QMouseEvent *ev);
       //鼠标移动事件
       void mouseMoveEvent(QMouseEvent *ev);
       //进入窗口区域
       void enterEvent(QEvent *);
       //离开窗口区域
       void leaveEvent(QEvent *);
    
    signals:
    
    public slots:
    };
    
    #endif // MYLABEL_H

![20190725150415352.png][]

#include "mylabel.h"
    #include <QMoveEvent>
    #include <QtDebug>
    MyLabel::MyLabel(QWidget *parent) : QLabel(parent)
    {
        //设置追踪鼠标
        this->setMouseTracking(true);
    }
    void MyLabel::mousePressEvent(QMouseEvent *ev)
    {
       int i = ev->x();
       int j = ev->y();
       //sprinf
       /*
        * QString str = QString("abc %1 ^_^ %2").arg(123).arg("mike");
        * str = abc 123 ^_^ mike
        */
         if(ev->button()==Qt::LeftButton)
         {
             qDebug() << "left";
         }
         else if(ev->button()==Qt::RightButton)
         {
            qDebug() << "Right";
         }
         else if(ev->button()==Qt::MidButton)
         {
             qDebug() << "mid";
         }
       QString text = QString("<center><h1>Mouse Press:(%1,%2)</h1></center>").arg(i).arg(j);
    
       this->setText(text);
    }
    
    void MyLabel::mouseReleaseEvent(QMouseEvent *ev)
    {
        QString text = QString("<center><h1>Mouse Release:(%1,%2)</h1></center>").arg(ev->x()).arg(ev->y());
    
        this->setText(text);
    }
    
    void MyLabel::mouseMoveEvent(QMouseEvent *ev)
    {
    
        QString text = QString("<center><h1>Mouse move:(%1,%2)</h1></center>").arg(ev->x()).arg(ev->y());
    
    //    this->setText(text);
    }
    
    void MyLabel::enterEvent(QEvent *e)
    {
        QString text = QString("<center><h1>Mouse enter</h1></center>");
        this->setText(text);
    }
    
    void MyLabel::leaveEvent(QEvent *e)
    {
        QString text = QString("<center><h1>Mouse leave</h1></center>");
        this->setText(text);
    }

![2019072515053384.png][]

#ifndef MYWIDGET_H
    #define MYWIDGET_H
    
    #include <QWidget>
    
    namespace Ui {
    class MyWidget;
    }
    
    class MyWidget : public QWidget
    {
        Q_OBJECT
    
    public:
        explicit MyWidget(QWidget *parent = 0);
        ~MyWidget();
    
    protected:
        //键盘按下事件
       void keyPressEvent(QKeyEvent *);
        //计时器事件
        void timerEvent(QTimerEvent *);
       //关闭事件
        void closeEvent(QCloseEvent *);
    
    private:
        Ui::MyWidget *ui;
    
        int timerId;
        int timerId2;
    };
    
    #endif // MYWIDGET_H

![20190725150627644.png][]

#include "mywidget.h"
    #include "ui_mywidget.h"
    #include <QDebug>
    #include <QKeyEvent>
    #include <QCloseEvent>
    #include <QMessageBox>
    MyWidget::MyWidget(QWidget *parent) :
        QWidget(parent),
        ui(new Ui::MyWidget)
    {
        ui->setupUi(this);
      timerId = this->startTimer(1000); //毫秒为单位，每隔一秒触发一次定时器
      this->timerId2=this->startTimer(500);
    }
    
    MyWidget::~MyWidget()
    {
        delete ui;
    }
    
    void MyWidget::keyPressEvent(QKeyEvent *event)
    {
        qDebug() << event->key();
        if(event->key() == Qt::Key_A)
            {
              qDebug() << "Qt::Key_A";
            }
    }
    
    void MyWidget::timerEvent(QTimerEvent *e)
    {
        if(e->timerId() == this->timerId)
        {
            static int sec = 0;
              ui->label->setText(
                        QString("<center><h1>timer out: %1</h1></center>").arg(sec++)
                        );
             if(sec == 5)
             {
                 //停止定时器
                 this->killTimer(this->timerId);
             }
        }
        else if(e->timerId() == this->timerId2)
        {
            static int sec = 0;
              ui->label_2->setText(
                        QString("<center><h1>timer out: %1</h1></center>").arg(sec++)
                        );
        }
    
    }
    
    
    void MyWidget::mousePressEvent(QMouseEvent *e)
    {
        qDebug() << "ssssssssssssssssssss";
    }
    
    void MyWidget::closeEvent(QCloseEvent *e)
    {
      int ret = QMessageBox::question(this,"question","是否需要关闭窗口");
             if(ret == QMessageBox::Yes)
             {
               //关闭窗口
              //处理关闭窗口，接收事件，事件就不会再往下传递
              e->accept();
               }
              else
             {
                //不关闭窗口
              //忽略事件，事件继续给父组件传递
               e->ignore();
               }
    }

![20190725204723405.png][]

#ifndef MYBUTTON_H
    #define MYBUTTON_H
    
    #include <QObject>
    #include <QWidget>
    #include <QPushButton>
    class MyButton : public QPushButton
    {
        Q_OBJECT
    public:
        explicit MyButton(QWidget *parent = 0);
    protected:
        void mousePressEvent(QMouseEvent *e);
    
    signals:
    
    public slots:
    };
    
    #endif // MYBUTTON_H

![20190725204834674.png][]

#include "mybutton.h"
    #include <QMouseEvent>
    #include <QDebug>
    MyButton::MyButton(QWidget *parent) : QPushButton(parent)
    {
    
    }
    void MyButton::mousePressEvent(QMouseEvent *e)
    {
        if(e->button() == Qt::LeftButton)
        {
            //如果是左键按下
            qDebug() << "按下的是左键";
            //事件接收后，就会往下传递
           e->ignore();//忽略，事件继续往下传递，给谁传递
                       //事件传递给了父组件，不是给父类（基类）
        }
        else
        {
            //不做处理
            QPushButton::mousePressEvent(e);
            //事件的忽略，事件继续往下传递
        }
    }

![2019072515071565.png][]

### 2）将MyLabel，MyButton类提升为基类 ###

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzMTM0MjA4NDc3Ng_size_16_color_FFFFFF_t_70 2][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzMTM0MjA4NDc3Ng_size_16_color_FFFFFF_t_70 3][]

### 效果： ###

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzMTM0MjA4NDc3Ng_size_16_color_FFFFFF_t_70 4][]             ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzMTM0MjA4NDc3Ng_size_16_color_FFFFFF_t_70 5][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzMTM0MjA4NDc3Ng_size_16_color_FFFFFF_t_70 6][]        ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzMTM0MjA4NDc3Ng_size_16_color_FFFFFF_t_70 7][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzMTM0MjA4NDc3Ng_size_16_color_FFFFFF_t_70 8][]   ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzMTM0MjA4NDc3Ng_size_16_color_FFFFFF_t_70 9][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3pzMTM0MjA4NDc3Ng_size_16_color_FFFFFF_t_70 10][]

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[20190725150214335.png]: /images/20211122/1a74214df48d4bb5909de2390207dbf2.png
[20190725150415352.png]: /images/20211122/fda4791142ee4016acadec3ff4aeaebf.png
[2019072515053384.png]: /images/20211122/e211e7746b354a2289a5981e9db9319a.png
[20190725150627644.png]: /images/20211122/69d064127ac94e9d892459f0771770b0.png
[20190725204723405.png]: /images/20211122/cd98884caa384f41b48907d86872f386.png
[20190725204834674.png]: /images/20211122/8d94f1bcdd2e4617b51f9cf16866e804.png
[2019072515071565.png]: /images/20211122/2bbd303019344266a5f349143224c7cd.png
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