Head file

#ifndef FIRSTEVENT_H
#define FIRSTEVENT_H

#include <QMainWindow>
#include <QMouseEvent>
#include <QKeyEvent>
#include <QEvent>

namespace Ui {
class FirstEvent;
}

class FirstEvent : public QMainWindow
{
    Q_OBJECT

public:
    explicit FirstEvent(QWidget *parent = 0);
    ~FirstEvent();

    //鼠标事件
    void mousePressEvent(QMouseEvent *);
    void mouseReleaseEvent(QMouseEvent *);
    void mouseMoveEvent(QMouseEvent* e);

    //键盘事件
    void keyPressEvent(QKeyEvent *evt);

    //evnet
    bool event(QEvent *event);

private:
    Ui::FirstEvent *ui;
};

#endif // FIRSTEVENT_H

CPP file

#include "firstevent.h"
#include "ui_firstevent.h"
#include <QDebug>


FirstEvent::FirstEvent(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::FirstEvent)
{
    ui->setupUi(this);
}

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


void FirstEvent::mousePressEvent(QMouseEvent *)
{
    qDebug()<<"鼠标按下";
}
void FirstEvent::mouseReleaseEvent(QMouseEvent *)
{
    qDebug()<<"鼠标释放";
}

void FirstEvent::mouseMoveEvent(QMouseEvent *e)
{
    ui->label->move(e->pos());
}


void FirstEvent::keyPressEvent(QKeyEvent *evt)
{
    int key = evt->key();//键盘键值
    qDebug()<<key;
    int x = ui->label->x();
    int y = ui->label->y();

    switch (key) {
    case Qt::Key_A:
    case Qt::Key_Left:
        ui->label->move(x-10,y);
        break;
    case Qt::Key_D:
    case Qt::Key_Right:
        ui->label->move(x+10,y);
        break;
    case Qt::Key_W:
    case Qt::Key_Up:
        ui->label->move(x,y-10);
        break;
    case Qt::Key_S:
    case Qt::Key_Down:
        ui->label->move(x,y+10);
        break;
    default:
        break;
    }
}

bool FirstEvent::event(QEvent *event)
{
    static int i=0;
    //qDebug()<<"******************"<<i++;
    return QMainWindow::event(event);
}

References

Qt5鼠标和键盘事件的简单示例 http://www.echojb.com/qt/2017/12/25/473349.html