QT 1.17

.cpp

#include "widget.h"
#include "ui_widget.h"
#include <QPainter>
#include <QDebug>
Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    ui->horizontalSlider->setMaximum(410);
    ui->horizontalSlider->setMinimum(130);

    connect(ui->horizontalSlider,SIGNAL(valueChanged(int)),this,SLOT(hSliderValueChangedSlot(int)));
}

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

void Widget::paintEvent(QPaintEvent *)
{
    QPainter p (this);
    p.translate( this->width()/2 , this->height() /2 );
    p.drawPixmap(-200,-200,400,400,QPixmap(":/rs/Pan.png"));

    p.rotate(   ui->horizontalSlider->value()    );

    p.drawPixmap(-15,-15,150,30,QPixmap(":/rs/Point.png"));
}
void Widget::hSliderValueChangedSlot(int)
{
    qDebug()<<__func__;
    //通知，整个窗口重绘
    this->update();
}

.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>

QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = nullptr);
    ~Widget();
    void paintEvent(QPaintEvent *);
public slots:
    void hSliderValueChangedSlot(int);
private:
    Ui::Widget *ui;
};
#endif // WIDGET_H