void MainWidget::showEvent(QShowEvent *event)
{
	//全屏
    showFullScreen();

	//动态加载背景图片
    QPixmap pixmap("../images/bg.png");
    QPixmap bgpixmap = pixmap.scaled(width(), height(), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);  // 饱满填充
    QPalette palette;
    palette.setBrush(QPalette::Window, QBrush(bgpixmap));
    setPalette(palette);
}