Qt小例子学习53 - 使用resizeEvent调整窗口大小时调整Qlabel的图像大小

Qt小例子学习53 - 使用resizeEvent调整窗口大小时调整Qlabel的图像大小

testsize.h

#ifndef TESTSIZE_H
#define TESTSIZE_H

#include 

class QLabel;

class testsize : public QWidget {
  Q_OBJECT

public:
  explicit testsize(QWidget *parent = 0);
  ~testsize();

private:
  QLabel *image;
  QPixmap original_px;

protected:
  void resizeEvent(QResizeEvent *event);
};

#endif // TESTSIZE_H

testsize.cpp

#include "testsize.h"

#include 
#include 
#include 

testsize::testsize(QWidget *parent) : QWidget(parent)
{
    image = new QLabel(this);
    original_px = QPixmap(":/wallpaper.jpg");
    image->setPixmap(original_px);
    resize(640, 480);
}
testsize::~testsize() {}
void testsize::resizeEvent(QResizeEvent *event)
{
    QPixmap px = original_px.scaled(event->size());
    image->setPixmap(px);
    image->resize(event->size());
    QWidget::resizeEvent(event);
}

main.cpp

#include "testsize.h"
#include 

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    testsize w;
    w.show();
    return a.exec();
}