QT event 是一種機制，

可以重新實現物件的
mouse(Press/Release/Move/DoubleClick)Event(QMouseEvent *e);

keyEvent

paintEvent

這裡重新實現MainWindow物件跟蹤滑鼠事件，並顯示出來

#include <QMainWindow>
#include <QLabel>
#include <QMouseEvent>
#include <QStatusBar>
class MouseEvent:public QMainWindow
{
    Q_OBJECT
    public
 
:
        MouseEvent(QWidget *parent=0);
        ~MouseEvent();
    protected:
        void mousePressEvent(QMouseEvent *e);
        void mouseMoveEvent(QMouseEvent *e);
        void mouseReleaseEvent(QMouseEvent *e);
    private:
        QLabel *mouseStatus;
};

#include "MouseEvent.h"
#include <QString>
 

MouseEvent::MouseEvent(QWidget *parent)
:QMainWindow(parent)
{
    mouseStatus=new QLabel(tr(""),this);
    statusBar()->addPermanentWidget(mouseStatus);
    resize(400,200);
    setMouseTracking(true);  
}

MouseEvent::~MouseEvent( )
{

}

void MouseEvent::mousePressEvent(QMouseEvent *e)
{
    QString
 
 button_str;
    if(e->button()==Qt::LeftButton)
        button_str=tr("left click ");
    if(e->button()==Qt::RightButton)
        button_str=tr("right click ");
    QString str="("+QString::number(e->x())+","+QString::number(e->y())+")";
    mouseStatus->setText(button_str+tr("Positon")+str);
}

void MouseEvent::mouseMoveEvent(QMouseEvent *e)
{
    QString str="("+QString::number(e->x())+","+QString::number(e->y())+")";
    mouseStatus->setText(tr("Positon")+str);
}

void MouseEvent::mouseReleaseEvent(QMouseEvent *e)
{
    QString str="("+QString::number(e->x())+","+QString::number(e->y())+")";
    mouseStatus->setText(tr("Release Positon")+str);
}