QT 编程如何让图像跟着窗体的大小而变化

Quote:#ifndef IMAGEWIDGET_HPP#define IMAGEWIDGET_HPP#include <QtCore>#include <QtGui>class ImageWidget : public QWidget{Q_OBJECTpublic:     ImageWidget(QWidget *parent = 0, Qt::WindowFlags f = 0);     virtual ~ImageWidget();protected:     void resizeEvent(QResizeEvent *event);private:     QImage _image;};#endifCPP文件: ImageWidget.cppQuote:#include "ImageWidget.hpp"ImageWidget::ImageWidget(QWidget *parent, Qt::WindowFlags f): QWidget(parent, f){     _image.load("image/image_background");     setAutoFillBackground(true);   // 这个属性一定要设置     QPalette pal(palette());     pal.setBrush(QPalette::Window,     QBrush(_image.scaled(size(), Qt::IgnoreAspectRatio,     Qt::SmoothTransformation)));     setPalette(pal);}ImageWidget::~ImageWidget(){}// 随着窗体变化而设置背景void ImageWidget::resizeEvent(QResizeEvent *event){     QWidget::resizeEvent(event);     QPalette pal(palette());     pal.setBrush(QPalette::Window,     QBrush(_image.scaled(event->size(), Qt::IgnoreAspectRatio,     Qt::SmoothTransformation)));     setPalette(pal);}