Qt QLable response click click event

https://blog.csdn.net/usister/article/details/76098620
first method

Use eventFilter event filter, with reference to specific methods  https://www.devbean.net/2012/10/qt-study-road-2-event-filter/

Renderings

The main code

  
  
#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui( new Ui::MainWindow)
{
ui-> setupUi ( this );
ui-> label-> installEventFilter ( the this ); // event filter installation
}

~ MainWindow :: MainWindow ()
{
delete ui;
}

bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
IF (obj == ui-> label) // specify a QLabel
{
if (event->type() == QEvent::MouseButtonPress) //mouse button pressed
{
QMouseEvent *mouseEvent = static_cast<QMouseEvent*>(event);
if(mouseEvent->button() == Qt::LeftButton)
{
:: Information QMessageBox ( NULL , "click" , "click me" ,
QMessageBox::Yes|QMessageBox::No,QMessageBox::Yes);
return true;
}
else
{
return false;
}
}
else
{
return false ;
}
}
else
{
// pass the event on to the parent class
return QMainWindow::eventFilter(obj, event);
}
}
  
  

The second method

Using inheritance QLabel, rewriting the event handler callback function mousePressEvent

Renderings

The main code

  
  
#include "mylabel.h"

MyLabel::MyLabel( const QString & text,QWidget *parent) : QLabel(parent)
{
setText(text);
}

MyLabel::MyLabel(QWidget *parent) : QLabel(parent)
{

}

void MyLabel::mousePressEvent(QMouseEvent *event)
{
//Qt::LeftButton
//Qt::RightButton
if(event->button()== Qt::LeftButton)
{
:: Information QMessageBox ( NULL , "click" , "click me" ,
QMessageBox::Yes|QMessageBox::No,QMessageBox::Yes);
}
}
  
  

The third method

Rewrite event()function

The main code

  
  
#include "mylabel.h"

MyLabel::MyLabel( const QString & text,QWidget *parent) : QLabel(parent)
{
setText(text);
}

MyLabel::MyLabel(QWidget *parent) : QLabel(parent)
{

}

bool MyLabel::event(QEvent *e)
{
if (e->type() == QEvent::MouseButtonPress)
{
QMouseEvent *mouseEvent = static_cast<QMouseEvent*>(e);
if(mouseEvent->button() == Qt::LeftButton)
{
:: Information QMessageBox ( NULL , "click" , "click me" ,
QMessageBox::Yes|QMessageBox::No,QMessageBox::Yes);
return true;
}
}
return QLabel::event(e);
}
  
  

All three methods of engineering the code upload to csdn, Qt 5.9.0