//本例设置的图片是在按钮上
QSize sz(38, 38);
QPixmap pixmap = m_pixmapList.at(i).scaled(sz, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);//m_pixmapList.at(i)为QPixmap的对象
QPixmap dest(38, 38);
dest.fill(Qt::transparent);
QPainter painter(&dest);
// 抗锯齿 + 平滑边缘处理
painter.setRenderHints(QPainter::Antialiasing, true);
painter.setRenderHints(QPainter::SmoothPixmapTransform, true);
// 裁剪为圆角
QPainterPath path;
path.addEllipse(0, 0, 38, 38);
painter.setClipPath(path);
painter.drawPixmap(0, 0, 38, 38, pixmap);
QIcon personnelico(dest);
m_approverBtn->setIcon(personnelico);
m_approverBtn->setIconSize(size);