3.Qt GUI中一些操作记录

一、如何在Widget中利用代码添加背景图片

 this->setAutoFillBackground(true); //
 QPalette palette = this->palette();
 palette.setBrush(QPalette::Window,
            QBrush(QPixmap(":/images/bg2.jpg").scaled(// 缩放背景图.
                        this->size(),
                        Qt::IgnoreAspectRatio,
                        Qt::SmoothTransformation)));
 this->setPalette(palette);

二、如何在QLabel中缩放图片

 void text::setpixmap(const QString &filename, QLabel *label)
 {
     QImage Image;
     Image.load(filename);
     QPixmap pixmap = QPixmap::fromImage(Image);
     int with = label->width();
     int height= label->height();
     QPixmap fitpixmap = pixmap.scaled(with,height,Qt::KeepAspectRatio,Qt::SmoothTransformation);//按比例缩放
 //    QPixmap fitpixmap = pixmap.scaled(with,height,Qt::IgnoreAspectRatio,Qt::SmoothTransformation);//饱满填充
     label->setPixmap(fitpixmap);
 }

三、