思路：先画一个线条，然后旋转坐标系再画其他线条，突出颜色的线条可以画死再旋转，也可以按照角度递增让特定线画突出颜色（这里使用的是这种）。

LoadingBarA::LoadingBarA(QWidget *parent) :  QWidget(parent){  timer = new QTimer(this); //定时器  timer->setInterval(50);  connect(timer,QTimer::timeout,this,[=](){    if(pointRect<=rectCount){      pointRect++;    }else{      pointRect = pointRect%rectCount;    }    update();  });}void LoadingBarA::paintEvent(QPaintEvent *event){ //重绘事件  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);  float degree = 360.0/rectCount; //rectCount:共有多少根线条  for(int i =0;isave();  painter->setPen(Qt::NoPen);  painter->setBrush(color);  QRect rect(arcLength,-rectHeight/2,rectWidth,rectHeight);  painter->drawRoundedRect(rect,rectHeight/2,rectHeight/2);  painter->restore();}void LoadingBarA::setDarkColor(QColor tempColor){  this->darkColor = tempColor;  update();}void LoadingBarA::setLightColor(QColor lightColor){  this->lightColor = lightColor;  update();}void LoadingBarA::setRectWidth(int l){  this->rectWidth = l;  update();}void LoadingBarA::setRectHeight(int l){  this->rectHeight = l;  update();}void LoadingBarA::setArcLength(int l){  this->arcLength = l;  update();}void LoadingBarA::setRectCount(int l){  this->rectCount = l;  update();}void LoadingBarA::startLoading(){ //设置开始  timer->start();}