Qt 圖片隨窗口改變

#include <QApplication>
#include <QWidget>
#include <QPainter>
#include <QBrush>
#include <QPicture>
#include <QFont>
#include <QtGui>

class PainterWidget: public QWidget
{
  protected:
    void paintEvent(QPaintEvent *);

};

void PainterWidget::paintEvent(QPaintEvent *event)
{

 

   /************************
    圖片隨窗體改變而改變
    ************************/

    QLabel *label = new QLabel;
    label->setPixmap(QPixmap("c:/painterwidget/images/house.png"));
    label->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored); //忽視初始圖片值
    label->setScaledContents(true);  //設置可改變的內容

    QScrollArea *scroll=new QScrollArea;

    scroll->setWidgetResizable(true);

    scroll->setWidget(label);

    QHBoxLayout *main=new QHBoxLayout;
    main->addWidget(scroll);
    setLayout(main);

}

int main(int argc,char **argv)
{
  QApplication app(argc,argv);
  PainterWidget pWidget;
  pWidget.resize(400,400);
  pWidget.show();

  return app.exec();
}