Qt之生成png/jpg/bmp格式图片_qt生成图片-CSDN博客

(1)使用QPainter 

示例关键代码：

    QImage image(QSize(this->width(),this->height()),QImage::Format_ARGB32);image.fill("white");QPainter *painter = new QPainter(&image);painter->save();QPen pen;pen.setWidth(2);pen.setColor(Qt::red);painter->setPen(pen);painter->drawEllipse(QPoint(width()/2,height()/2),50,50);painter->drawLine(QPointF(0,0),QPointF(width()/2,height()/2));painter->drawRect(QRect(40,40,150,160));painter->restore();painter->end();QString path=QApplication::applicationDirPath()+"/1.png";qDebug()<<path;image.save(path);

再提取：

    QImage image(QSize(this->width(),this->height()),QImage::Format_ARGB32);image.fill("white");QPainter *painter = new QPainter(&image);painter->save();//使用QPainter进行绘制//...painter->end();//保存为图片QString path=QApplication::applicationDirPath()+"/1.png";image.save(path);

就是在QImage上绘制图像，再保存为图片。

(2)直接把QWidget窗体上的内容保存为图片。

示例代码：

    Widget w;w.show();QPixmap pixmap(w.size());w.render(&pixmap);QString path=QApplication::applicationDirPath()+"/3.png";pixmap.save(path);

参考：

保存Qwiget 图像 并调整大小-QT开发中文网 (0voice.com)