Qt实现图片旋转

Qt实现图片旋转

/* 头文件 */class MainWindow : public QMainWindow{    Q_OBJECTpublic:    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);}