QT QLabel 单击事件

 

 

有2种方法 最实用的就是用eventFilter的方式

 

mainwindow.h 

 

#ifndef MAINWINDOW_H

#define MAINWINDOW_H

#include <QMainWindow>

#include <QLabel>

namespace Ui {

    class MainWindow;

}

class MainWindow : public QMainWindow

{

    Q_OBJECT

public:

   // explicit

    MainWindow(QWidget *parent = 0);

    ~MainWindow();

private:

   // Ui::MainWindow *ui;

      QLabel *l1;

       QLabel *l2;

protected:

     bool eventFilter(QObject *obj, QEvent *ev);

};

#endif // MAINWINDOW_H

*************************************

mainwindow.cpp

#include "mainwindow.h"

#include "ui_mainwindow.h"

#include <QLabel>

#include <QKeyEvent>

#include "qDebug"

#include "QMessageBox"

#include <QtGui>

MainWindow::MainWindow(QWidget *parent) :

    QMainWindow(parent)

    //,

  //  ui(new Ui::MainWindow)

{

    //ui->setupUi(this);

   l1 = new QLabel(this);

     l2 = new QLabel(this);

   l1->setText("123");

   l2->setText("345");

   QGridLayout *tt1 = new QGridLayout(this);

   tt1->addWidget(l1,6,6);

      tt1->addWidget(l2,1,3);

   QWidget * w = new QWidget(this);

   w->setLayout(tt1);

         this->setCentralWidget(w);

  l1->installEventFilter(this);

}

bool MainWindow::eventFilter(QObject *obj, QEvent *event)

{

    if (obj == l1) {

        if (event->type() == QEvent::MouseButtonPress) { 

              QMessageBox::information(NULL, QString::fromLocal8Bit("单击"), QString::fromLocal8Bit("单击确定"), QMessageBox::Yes | QMessageBox::No, QMessageBox::Yes);

            return true;

        } else {

            return false;

        }

    } else {

        // pass the event on to the parent class

        return QMainWindow::eventFilter(obj, event);

    }

}

MainWindow::~MainWindow()

{

   // delete ui;

}

*************************************************

第2种内部得到单击事件,继承子QLabel

mainwindow.h

#ifndef MAINWINDOW_H

#define MAINWINDOW_H

class QLabel;

class myLabel;

#include <QMainWindow>

namespace Ui {

    class MainWindow;

}

class MainWindow : public QMainWindow

{

    Q_OBJECT

public:

   // explicit

    MainWindow(QWidget *parent = 0);

    ~MainWindow();

private:

  //  Ui::MainWindow *ui;

    QLabel *l1;

    myLabel *m_label;

};

#endif // MAINWINDOW_H

******************************

MYLABEL.H

#ifndef MYLABEL_H

#define MYLABEL_H

#include <QLabel>

#include <QWidget>

#include <QString>

#include <QMainWindow>

class myLabel : public QLabel

{

        Q_OBJECT

public:

   myLabel(const QString & text, QWidget * parent = 0);

        ~myLabel(){}

signals:

        void clicked();

public slots:

void slotClicked();

protected:

    public:

        void mousePressEvent ( QMouseEvent * event ) ;

};

#endif // MYLABEL_H  

*********************

mainwindow.cpp

#include "mainwindow.h" 

#include "ui_mainwindow.h"

#include "myLabel.h"

#include <QtGui>

#include <QString>

MainWindow::MainWindow(QWidget *parent) :

    QMainWindow(parent)

   // , ui(new Ui::MainWindow)

{

//ui->setupUi(this);

m_label = new myLabel("123",this);

m_label->setText(QString::fromLocal8Bit("单击"));

QLabel *l1=new QLabel;

l1->setText("1234");

QGridLayout *tt1 = new QGridLayout(this);

tt1->addWidget(m_label,1,0);

tt1->addWidget(l1,2,0);

QWidget * w = new QWidget(this);

w->setLayout(tt1);

this->setCentralWidget(w);

 this->setWindowTitle(tr("main"));

}

MainWindow::~MainWindow()

{

    //delete ui;

}

***************************** 

MYLABEL.CPP

#include "myLabel.h"

#include "qdebug.h"

#include "QMessageBox"

#include "mainwindow.h"

#include "QString"

myLabel::myLabel( const QString & text, QWidget * parent )

    :QLabel(parent)

{

 connect(this, SIGNAL(clicked()), this, SLOT(slotClicked()));

}

void myLabel::slotClicked()

{

 QMessageBox::information(NULL, QString::fromLocal8Bit("单击"), QString::fromLocal8Bit("单击确定"), QMessageBox::Yes | QMessageBox::No, QMessageBox::Yes);

}

void myLabel::mousePressEvent(QMouseEvent *event)

{

        emit clicked();

}