void aaq::paintEvent( QPaintEvent* ev )

{

    QPainter painter(this);

    // 去除画笔

    painter.setPen(Qt::NoPen);

    // 设置反锯齿

    painter.setRenderHint(QPainter::Antialiasing);

    //******************************************** 圆饼图 *****************************************//

    if()

    {

        // 顶层圆面

        QRectF rect_top(10.0, 20.0, 280.0, 160.0);

        // 底层圆面

        QRectF rect_bottom(10.0, 60.0, 280.0, 160.0);

        // 中间矩形

        QRectF rect_midd(10.0, 100.0, 280.0, 40.0);

        // 扇形起始角度

        int startAngle =  * ;

        // 扇形覆盖范围

        int spanAngle =  * ;

        painter.setBrush(QColor(,,,));

        // 绘制底层圆面

        painter.drawEllipse(rect_bottom);

        // 绘制中间矩形

        painter.drawRect(rect_midd);

        painter.setBrush(QColor(Qt::darkYellow));

        // 绘制底层扇形

        painter.drawPie(rect_bottom, startAngle, spanAngle);

        // 扇形的弦与弧的交点

        double pi = 3.1415926;

        double dx1 = rect_top.width() * 0.5 * cos( * pi / );

        double dy1 = rect_top.height() * 0.5 * sin( * pi / );

        double dx2 = rect_top.width() * 0.5 * cos( * pi / );

        double dy2 = rect_top.height() * 0.5 * sin( * pi / );

        // 求交点的坐标值

        QPointF posBackCenter = QPointF(rect_top.center());

        double dX1 = posBackCenter.x() + dx1 + 0.5;

        double dY1 = posBackCenter.y() - dy1 + 0.5;

        double dX2 = posBackCenter.x() + dx2 + 0.5;

        double dY2 = posBackCenter.y() - dy2 + 0.5;

        // 记录交点

        QPointF topLeft = QPointF(dX1, dY1);

        QPointF bottomRight = QPointF(dX2, dY2) + QPointF(,);

        QPointF bottomLeft = topLeft + QPointF(,);

        painter.setBrush(QColor(Qt::darkYellow));

        // 绘制连接扇形的区域

        QPolygonF path;

        path << topLeft << QPointF(dX2,dY2) << bottomRight << bottomLeft;

        painter.drawPolygon(path);

        // 绘制顶层圆面

        painter.setBrush(QColor(,,,));

        painter.drawEllipse(rect_top);

        // 绘制顶层扇形

        painter.setBrush(QColor(Qt::yellow));

        painter.drawPie(rect_top, startAngle, spanAngle);

    }

    QWidget::paintEvent(ev);

}