void CMPassrate2::paintEvent(QPaintEvent *event){//界面繪制事件 int width = this->width(); int height = this->height(); int side = qMin(width, height); QPainter painter(this); painter.setRenderHints(QPainter::Antialiasing | QPainter::TextAntialiasing); painter.translate(width / 2, height / 2); painter.scale(side / 200.0, side / 200.0); drawBGE(&painter); //畫背景圓 drawTextE(&painter);//畫文字所在圓弧 drawText(&painter);//畫文字 drawLines(&painter);//畫最外部的線}void CMPassrate2::updateValue(float value){//提供給外部的方法，用于更新value this->value = value; update();//每次更新value后，都重繪界面}void CMPassrate2::drawLines(QPainter* painter){ painter->save(); QPen pen; pen.setColor(QColor("#A7DD42")); pen.setWidth(2); painter->setPen(pen); float range = 270.0/lineCount; //自定義所有的線加起來占270度，100條線 painter->rotate(135);//旋轉135度，開始畫線，總共畫270度。 QLine line(QPoint(outLineRadius,0),QPoint(innLineRadius,0)); for(int i = 1;i<=lineCount;i++){  if(i>value){   QPen pen;   pen.setColor(QColor("#D7D7D7"));   pen.setWidth(2);   painter->setPen(pen);  }  painter->drawLine(line);  painter->rotate(range); } painter->restore();}void CMPassrate2::drawBGE(QPainter* painter){ painter->save(); painter->setPen(Qt::NoPen); painter->setBrush(QColor("#EAEAEA")); QRect rect(-bgERadius,-bgERadius,bgERadius*2,bgERadius*2); painter->drawEllipse(rect); painter->restore();}void CMPassrate2::drawTextE(QPainter* painter){ painter->save(); painter->setPen(Qt::NoPen); painter->setBrush(QColor("#2DC877")); QPainterPath path; QRect rectOut(-textOutRadius,-textOutRadius,textOutRadius*2,textOutRadius*2); path.arcTo(rectOut,0,360); QPainterPath subPath; QRect rectInn(-textInnRadius,-textInnRadius,textInnRadius*2,textInnRadius*2); subPath.addEllipse(rectInn); path -= subPath; painter->drawPath(path); painter->restore();}void CMPassrate2::drawText(QPainter* painter){ painter->save(); painter->setPen(QColor("#62A0DB")); QRect rectInn(-textInnRadius,-textInnRadius,textInnRadius*2,textInnRadius*2); QFont font = painter->font(); font.setPixelSize(textSize); painter->setFont(font); painter->drawText(rectInn,Qt::AlignCenter,QString::number(value)); painter->restore();}