Qt 生成圆形图片

QPixmap PixmapToRound(const QPixmap &src, int radius)
{
    if (src.isNull()) {
        return QPixmap();
    }

    QSize size(2*radius, 2*radius);
    QBitmap mask(size);
    QPainter painter(&mask);
    painter.setRenderHint(QPainter::Antialiasing);
    painter.setRenderHint(QPainter::SmoothPixmapTransform);
    painter.fillRect(0, 0, size.width(), size.height(), Qt::white);
    painter.setBrush(QColor(0, 0, 0));
    painter.drawRoundedRect(0, 0, size.width(), size.height(), 99, 99);

    QPixmap image = src.scaled(size);
    image.setMask(mask);
    return image;
}

	// 窗口top圆角处理
	int radius = 4;
	QSize maskSize(this->size().width(), this->size().height() + radius);
	QBitmap mask(maskSize);
	QPainter maskPainter(&mask);
	maskPainter.setRenderHint(QPainter::Antialiasing);
	maskPainter.setRenderHint(QPainter::SmoothPixmapTransform);
	maskPainter.fillRect(this->rect(), Qt::white);
	maskPainter.setBrush(QColor(0, 0, 0));
	maskPainter.drawRoundedRect(QRect(QPoint(0, 0), maskSize), radius, radius);
	this->setMask(mask);