Qt实现图片旋转

根据QWidget 或 QGraphicWidget体系调整所需要继承或更新的类实现

/* 头文件 */
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow(QWidget *parent = 0);
    ~MainWindow();
protected:
    void paintEvent(QPaintEvent *event);
}
/* cpp文件 */
MainWindow::MainWindow(QWidget *parent): QMainWindow(parent)
{
    /*定时更新*/
    QTimer *timer = new QTimer(this);
    connect( timer, SIGNAL(timeout()), this, SLOT( update() ) );
    timer->start(50);
}

void MainWindow::paintEvent(QPaintEvent *event)
{
    QPainter painter(this);

    QString pathName = "/home/test.png";
    QImage sourceImage;
    sourceImage.load(pathName);

    painter.setRenderHint( QPainter::Antialiasing );
    QColor quadColor( 0, 0, 255 );

    painter.setBrush( quadColor );
    QTime time = QTime::currentTime();
 
    painter.translate( 100, 100 );
    painter.rotate( ( time.second() + ( time.msec() / 1000.0 ) ) * 6.0 );

    /*下行为画出一个正方行旋转*/
    //painter.drawRect( QRect( -50, -50, 100, 100 ) );

    /* 下行将图片画出旋转， -50,-50 为旋转中心。 */
    painter.drawImage(QRect(-50, -50, sourceImage.width(), sourceImage.height()), sourceImage);
}