QT——Qcharts draws real-time curves

This article will use QT to implement a simple dynamic real-time curve . In the future, the data can be collected and made into a visualized curve.

renderings

1. After creating the project, add charts to the .Pro file

2. In the design, drag a Graphics View , and then promote it to QChartView

3. Add header files and namespaces

4. Create table

//创建表
void MainWindow::CreatCharts(){
    QChart *qchart = new QChart;

    //把chart放到容器里
    ui->graphicsView->setChart(qchart);
    //设置抗锯齿
    ui->graphicsView->setRenderHint(QPainter::Antialiasing);

    //创建两条线
    QLineSeries *ser0 = new QLineSeries;
    QLineSeries *ser1 = new QLineSeries;
    //设置名字
    ser0->setName("ser0");
    ser1->setName("ser1");
    //放入charts里
    qchart->addSeries(ser0);
    qchart->addSeries(ser1);

    //创建x坐标
    QDateTimeAxis *QaX = new QDateTimeAxis;
    //格式
    QaX->setFormat("hh:mm:ss");
    QaX->setTickCount(10);
    QaX->setTitleText("time");

    //创建y坐标
    QValueAxis *QaY = new QValueAxis;
    //设置范围
    QaY->setRange(-1,1);
    QaY->setTickCount(6);

    //将线条放入表中
    qchart->setAxisX(QaX,ser0);
    qchart->setAxisY(QaY,ser0);
    qchart->setAxisX(QaX,ser1);
    qchart->setAxisY(QaY,ser1);
}

5. Current effect

6. Next, draw the curve and create the QTimer class

7. Create a timer and slot function, and refresh the data once every 1s

8. Data update

//数据更新
void MainWindow::RefreshTime_Slot(){

    //获取当前时间
    QDateTime currentTime = QDateTime::currentDateTime();
    //获取随机数
    qsrand(QTime::currentTime().second());
    int rand  = qrand()%100;//获取0~10之间的数

    //获取初始化的qchart
    QChart *qchart =(QChart *)ui->graphicsView->chart();

    //获取之前的ser
    QLineSeries *ser0 = (QLineSeries *)ui->graphicsView->chart()->series().at(0);
    QLineSeries *ser1 = (QLineSeries *)ui->graphicsView->chart()->series().at(1);

    //更新数据
    ser0->append(currentTime.toMSecsSinceEpoch(),cos(rand));
    ser1->append(currentTime.toMSecsSinceEpoch(),sin(rand));

    qchart->axisX()->setMin(QDateTime::currentDateTime().addSecs(-1*30));
    qchart->axisX()->setMax(QDateTime::currentDateTime().addSecs(1*30));

    ui->label->setText(QTime::currentTime().toString("hh:mm:ss"));

}

QT——Qcharts draws real-time curves

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