QCustomPlot *plot = new QCustomPlot(parent);

QVector<double> x(100), y(100);
// 填充數(shù)據(jù)...
QCPGraph *graph = plot->addGraph();
graph->setData(x, y);

// 創(chuàng)建數(shù)據(jù)追蹤器
QCPItemTracer *tracer = new QCPItemTracer(plot);
tracer->setGraph(graph);
tracer->setGraphKey(5.0);  // 定位到X=5.0的點
// 添加十字坐標(biāo)線
QCPItemStraightLine *vLine = new QCPItemStraightLine(plot);
vLine->point1->setCoords(5, 0);  // (x,y)
vLine->point2->setCoords(5, 10);

// 創(chuàng)建繪圖區(qū)域
QCustomPlot *plot = new QCustomPlot(this);
// 生成數(shù)據(jù)
QVector<double> x(101), y(101);
for (int i=0; i<101; ++i) {
  x[i] = i/50.0 - 1;  // -1 到 1
  y[i] = x[i]*x[i];   // y = x2
}
// 添加曲線
plot->addGraph();
plot->graph(0)->setData(x, y);
// 設(shè)置坐標(biāo)軸
plot->xAxis->setLabel("X Axis");
plot->yAxis->setLabel("Y Axis");
plot->rescaleAxes();
// 重繪
plot->replot();

// 定時更新數(shù)據(jù)
QTimer *timer = new QTimer(this);
connect(timer, &QTimer::timeout, [&]() {
  static double t = 0;
  plot->graph(0)->addData(t, qSin(t));  // 追加新數(shù)據(jù)點
  plot->xAxis->setRange(t-10, t);       // 滾動X軸
  plot->replot();
  t += 0.1;
});
timer->start(50);  // 20 FPS刷新

// 主圖層：曲線圖
plot->addGraph();
// 創(chuàng)建新圖層（在頂部顯示標(biāo)注）
QCPLayer *annoLayer = new QCPLayer(plot, "annotations");
plot->addLayer("annotations", 0, QCustomPlot::limAbove); // 置于頂層
// 在標(biāo)注層添加文本
QCPItemText *textLabel = new QCPItemText(plot);
textLabel->setLayer(annoLayer);
textLabel->position->setCoords(5, 8);
textLabel->setText("峰值區(qū)域");

// 創(chuàng)建自定義彩色柱狀圖
QCPBars *bars = new QCPBars(plot->xAxis, plot->yAxis);
// 漸變著色
QVector<QColor> colors = {Qt::blue, Qt::green, Qt::red};
QSharedPointer<QCPColorGradient> gradient(new QCPColorGradient);
gradient->setColorStops({ {0, Qt::blue}, {0.5, Qt::green}, {1, Qt::red} });
// 應(yīng)用著色
bars->setBrush(QBrush(*gradient));

graph->setLineStyle(QCPGraph::lsNone);  // 禁用連線
graph->setScatterStyle(QCPScatterStyle::ssDot);  // 僅繪制點

plot->setOpenGl(true);  // 啟用GPU渲染

// 僅追加新數(shù)據(jù)（避免全量重設(shè)）
graph->addData(newX, newY);
graph->data()->removeBefore(newX-visibleRange);

plot->setReplotTime(20);  // 限制重繪頻率(ms)