Qt:绘制时，用线性渐变填充一个圆角矩形范围

void XXX::paintEvent(QPaintEvent *event)
{
    QPainter painter(this);
    //圆角矩形范围
    QPainterPath path;
    path.addRoundedRect(this->rect(),10,10);
    //渐变颜色设置
    QLinearGradient linearGrad(0,0,0,this->height());
    linearGrad.setColorAt(0,Qt::blue);
    linearGrad.setColorAt(1,Qt::red);
    //绘制
    painter.fillPath(path,linearGrad);
}