程序代码：

bg_image = QPixmap(ui->m_sb_bg_width->value() ,ui->m_sb_bg_height->value());
    bg_image.fill(Qt::transparent);//设置背景透明

    ui->label->setPixmap(bg_image);

    QString string = "./svg/1-1.svg";
    QSvgRenderer * svgImage = new QSvgRenderer();
    if(!svgImage->load(string))
    {
        MessageOut("svg解析出错");
    }
    QPainter p(&bg_image);
    svgImage->render(&p);

    ui->label->setPixmap(bg_image);