首先绘制区域扇形需要先注意一下几点：

1. QPainter中绘制完整的圆等于5760(16 * 360)，此处数值用于计算每一块扇形区域所显示的

1. 需要了解一下扇形二等分线的计算方法

1. 要注意做坐标原点转换

    /*此处为屏幕分辨率自适应*/const qreal ratioW = DesktopResize::GetInstance()->getWidthRatio();const qreal ratioH = DesktopResize::GetInstance()->getHeightRatio();const qreal ratioT = qMin(ratioW, ratioH);// 三角形和凸角必须指定为1/16度，即一个完整的圆等于5760(16 * 360)int circleArea = 5760;         // 设置圆弧显示区域    QRect rect(418 * ratioW, 340 * ratioH, 557  * ratioT, 557 * ratioT);// 圆半径int radius = rect.width() / 2;                  // 起始角度qreal startAngle = 0;// 当前绘制扇形所占角度qreal angle;//文字显示起始角度qreal textStartAngle = 0;// 文字显示角度qreal textAngle;// 需要统计的总数值int totalValue = 0;// _fanDataClassList为一个结构数据list，根据个人需要自行定义// 计算总数值for(int i = 0; i < _fanDataClassList.count(); i++){totalValue += _fanDataClassList.at(i).value;}// 计算每个数值的扇形显示区域for(int i = 0; i < _fanDataClassList.count(); i++){// 设置画笔颜色与画刷颜色保持一致，需要注意此处需要设设置画笔，否则会出现两个扇形之间显示有空白间隙QPen pen(_fanDataClassList.at(i).color, 1, Qt::SolidLine);painter->setPen(pen);// 设置画刷颜色与画笔保持一致painter->setBrush(_fanDataClassList.at(i).color);// 计算当前数值所占的百分比qreal persent = (double)_fanDataClassList.at(i).value / totalValue;// 根据百分比计算当前数值扇形尖角处所占角度的比例angle = circleArea * persent;// 通过path来获取当前绘制的扇形区域QPainterPath path;// 因圆心角需要在中位置来计算，将path起点移动到rect的中点位置path.moveTo(rect.center());// 创建一个占据给定矩形的弧，从指定的startAngle开始，逆时针扩展angle结束// 角度用角度来表示。顺时针弧线可以使用负角度指定。path.arcTo(rect, startAngle / 16, angle / 16);// 此处用来确定鼠标点击区域显示统计数据用，根据个人需要添加_pathValueMap.insert(i, path);// 绘制当前数值所占扇形区域painter->drawPath(path);// 如果不需要获取每块扇形的点击区域也可以直接使用drawPie绘制，就不需要使用path了//        painter->drawPie(rect, startAngle, angle);// 计算下一个扇形的起始角度startAngle += angle;}// 绘制每一块扇形区域的文字数目和占比统计painter->setBrush(Qt::NoBrush);for(int i=0; i < _fanDataClassList.count(); i++){if(_fanDataClassList.at(i).value == 0)continue;// 同样先计算当前数值的占比qreal persent = (double)_fanDataClassList.at(i).value / totalValue;// 计算文字显示角度textAngle = circleArea * persent;//各个对应扇形二等分线的角度qreal abc = 3.14 * 2 * (double)(textStartAngle + textAngle / 2) / circleArea;       // 根据二等分线计算出当前扇形区域边缘的终点坐标qreal valueX = radius * qCos(abc) + radius + rect.x();qreal valueY = -radius * qSin(abc) + radius + rect.y();// 计算终点坐标相对于圆心的坐标用以标定文字的显示方向QPointF point = QPointF(valueX, valueY) - rect.center();int lineX = 0;int lineY = 0;int lineWidth = 0;int textX = 0;// 根据数学坐标系判断该点坐标所处象限if(point.x() > 0 && point.y() < 0){lineX = 30  * ratioW;lineY = -30 * ratioH;lineWidth = 40 * ratioW;textX = valueX + lineX + lineWidth + 10 * ratioW;}else if(point.x() < 0 && point.y() < 0){lineX = -30 * ratioW;lineY = -30 * ratioH;lineWidth = -40 * ratioW;textX = valueX + lineX + lineWidth - 250 * ratioW;}else if(point.x() < 0 && point.y() > 0){lineX = -30 * ratioW;lineY = 30 * ratioH;lineWidth = -40 * ratioW;textX = valueX + lineX + lineWidth - 250 * ratioW;}else if(point.x() > 0 && point.y() > 0){lineX = 30 * ratioW;lineY = 30 * ratioH;lineWidth = 40 * ratioW;textX = valueX + lineX + lineWidth + 10 * ratioW;}// 绘制二等分线和延迟线及文字下划线， 以下代码较为简单就不做注解了QPen pen(_fanDataClassList.at(i).color, 1, Qt::SolidLine);pen.setCapStyle(Qt::RoundCap);pen.setJoinStyle(Qt::RoundJoin);painter->setPen(pen);QVector<QPointF> points;points.push_back(QPointF(valueX, valueY));points.push_back(QPointF(valueX + lineX, valueY + lineY));points.push_back(QPointF(valueX + lineX + lineWidth, valueY + lineY));painter->drawPolyline(QPolygonF(points));QFont font = painter->font();font.setPixelSize(22 * ratioT);font.setWeight(50);font.setBold(true);painter->setFont(font);pen.setColor(Qt::black);painter->setPen(pen);
//        painter->drawText(valueX - 20, valueY, QString("%1%").arg( QString::number((persent * 100), 'f', 1)));if(i == 0){painter->drawText(textX, valueY + lineY + 5 * ratioH, QString("正确率：100% %1人").arg(_fanDataClassList.at(i).value));}else if(i == 1){painter->drawText(textX, valueY + lineY + 5 * ratioH, QString("正确率：90%-99% %1人").arg(_fanDataClassList.at(i).value));}else if(i == 2){painter->drawText(textX, valueY + lineY + 5 * ratioH, QString("正确率：80%-89% %1人").arg(_fanDataClassList.at(i).value));}else if(i == 3){painter->drawText(textX, valueY + lineY + 5 * ratioH, QString("正确率：60%-79% %1人").arg(_fanDataClassList.at(i).value));}else{painter->drawText(textX, valueY + lineY + 5 * ratioH, QString("正确率：0%-59% %1人").arg(_fanDataClassList.at(i).value));}textStartAngle += textAngle;}

效果如图：