开源 C++ QT Widget 开发（三）图表--波形显示器

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTimer>

class MyWave;

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    MyWave *wave;
    QTimer *timer;
};

#endif // MAINWINDOW_H

3.2 mywave.h文件源码

#ifndef MYWAVE_H
#define MYWAVE_H

#include <QWidget>
#include <QtCharts>

QT_CHARTS_USE_NAMESPACE

class MyWave : public QWidget
{
    Q_OBJECT

public:
    explicit MyWave(QWidget *parent = nullptr);

    // 设置方法
    void setSize(const QSize &size);
    void setXRange(qreal min, qreal max);
    void setYRange(qreal min, qreal max);
    void setAxisTitle(const QString &xTitle, const QString &yTitle);
    void setBackgroundColor(const QColor &color);
    void setLine1Color(const QColor &color);
    void setLine2Color(const QColor &color);
    void setMaxDisplayPoints(int count);
    void appendData(qreal yValue1, qreal yValue2);
    void clearData();

protected:
    void resizeEvent(QResizeEvent *event) override;

private:
    void updateChart();

    QChart *m_chart;
    QChartView *m_chartView;
    QSplineSeries *m_series1;
    QSplineSeries *m_series2;
    QValueAxis *m_axisX;
    QValueAxis *m_axisY;

    QList<qreal> m_data1;
    QList<qreal> m_data2;
    int m_maxDisplayPoints = 200;
    qreal m_xCounter = 0;
};

#endif // MYWAVE_H

3.3 mainwindow.cpp文件源码

#include "mainwindow.h"
#include "mywave.h"
#include <QPushButton>
#include <QVBoxLayout>
#include <QHBoxLayout>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent)
{
    // 创建波形控件
    wave = new MyWave(this);
    wave->setSize(QSize(600, 300));
    wave->setXRange(0, 100);
    wave->setYRange(-10, 10);
    wave->setAxisTitle("时间", "数值");
    wave->setLine1Color(Qt::blue);
    wave->setLine2Color(Qt::red);
    wave->setMaxDisplayPoints(100);

    // 创建按钮控件
    QPushButton *startButton = new QPushButton("开始", this);
    QPushButton *stopButton = new QPushButton("停止", this);
    QPushButton *clearButton = new QPushButton("清除", this);

    // 设置按钮样式
    QString buttonStyle = "QPushButton {"
                         "  padding: 8px 16px;"
                         "  font-size: 14px;"
                         "  min-width: 80px;"
                         "  border-radius: 4px;"
                         "  background-color: #f0f0f0;"
                         "}"
                         "QPushButton:hover {"
                         "  background-color: #e0e0e0;"
                         "}";
    startButton->setStyleSheet(buttonStyle);
    stopButton->setStyleSheet(buttonStyle);
    clearButton->setStyleSheet(buttonStyle);

    // 创建水平布局放置按钮
    QHBoxLayout *buttonLayout = new QHBoxLayout();
    buttonLayout->addWidget(startButton);
    buttonLayout->addWidget(stopButton);
    buttonLayout->addWidget(clearButton);
    buttonLayout->addStretch();
    buttonLayout->setSpacing(10);

    // 创建垂直主布局
    QVBoxLayout *mainLayout = new QVBoxLayout();
    mainLayout->addLayout(buttonLayout);
    mainLayout->addWidget(wave);
    mainLayout->setContentsMargins(20, 20, 20, 20);
    mainLayout->setSpacing(15);

    // 设置中央部件
    QWidget *centralWidget = new QWidget(this);
    centralWidget->setLayout(mainLayout);
    setCentralWidget(centralWidget);
    this->setFixedSize(1200, 800);

    // 定时器用于模拟数据
    timer = new QTimer(this);
    bool isRunning = false;

    // 按钮信号连接
    connect(startButton, &QPushButton::clicked, [=, &isRunning]() {
        if (!isRunning) {
            timer->start(100);
            isRunning = true;
        }
    });

    connect(stopButton, &QPushButton::clicked, [=, &isRunning]() {
        timer->stop();
        isRunning = false;
    });

    connect(clearButton, &QPushButton::clicked, [this]() {
        wave->clearData();
    });

    connect(timer, &QTimer::timeout, [this]() {
        static qreal phase1 = 0;
        static qreal phase2 = 0;
        wave->appendData(
            qSin(phase1) * 10,
            qCos(phase2) * 8
        );
        phase1 += 0.1;
        phase2 += 0.15;
    });
}

MainWindow::~MainWindow()
{
    delete timer;
    delete wave;
}

3.4 mywave.cpp文件源码

#include "mywave.h"

MyWave::MyWave(QWidget *parent) : QWidget(parent)
{
    // 初始化图表
    m_chart = new QChart();

    // 初始化两条曲线
    m_series1 = new QSplineSeries();
    m_series2 = new QSplineSeries();
    m_chart->addSeries(m_series1);
    m_chart->addSeries(m_series2);

    // 初始化坐标轴
    m_axisX = new QValueAxis();
    m_axisY = new QValueAxis();
    setXRange(0, 200);
    setYRange(-10, 10);

    // 添加坐标轴
    m_chart->addAxis(m_axisX, Qt::AlignBottom);
    m_chart->addAxis(m_axisY, Qt::AlignLeft);
    m_series1->attachAxis(m_axisX);
    m_series1->attachAxis(m_axisY);
    m_series2->attachAxis(m_axisX);
    m_series2->attachAxis(m_axisY);

    // 默认样式
    setBackgroundColor(Qt::white);
    setLine1Color(Qt::blue);
    setLine2Color(Qt::red);
    m_chart->legend()->setVisible(true);
    m_series1->setName("曲线1");
    m_series2->setName("曲线2");
    m_chart->legend()->setAlignment(Qt::AlignBottom);

    // 初始化视图
    m_chartView = new QChartView(m_chart, this);
    m_chartView->setRenderHint(QPainter::Antialiasing);
    setSize(QSize(800, 400));
}

void MyWave::setSize(const QSize &size)
{
    this->resize(size);
    m_chartView->resize(size);
}

void MyWave::setXRange(qreal min, qreal max)
{
    m_axisX->setRange(min, max);
    m_axisX->setTickCount(10);
}

void MyWave::setYRange(qreal min, qreal max)
{
    m_axisY->setRange(min, max);
    m_axisY->setTickCount(10);
}

void MyWave::setAxisTitle(const QString &xTitle, const QString &yTitle)
{
    m_axisX->setTitleText(xTitle);
    m_axisY->setTitleText(yTitle);
}

void MyWave::setBackgroundColor(const QColor &color)
{
    m_chart->setBackgroundBrush(QBrush(color));
    m_chart->setBackgroundPen(QPen(color));
}

void MyWave::setLine1Color(const QColor &color)
{
    m_series1->setPen(QPen(color, 2));
}

void MyWave::setLine2Color(const QColor &color)
{
    m_series2->setPen(QPen(color, 2));
}

void MyWave::setMaxDisplayPoints(int count)
{
    m_maxDisplayPoints = count;
    setXRange(0, count);
}

void MyWave::appendData(qreal yValue1, qreal yValue2)
{
    m_data1.append(yValue1);
    m_data2.append(yValue2);
    m_xCounter++;

    if (m_data1.size() > m_maxDisplayPoints) {
        m_data1.removeFirst();
        m_data2.removeFirst();
    }

    updateChart();
}

void MyWave::clearData()
{
    m_data1.clear();
    m_data2.clear();
    m_xCounter = 0;
    m_series1->clear();
    m_series2->clear();
    updateChart();
}

void MyWave::updateChart()
{
    QVector<QPointF> points1, points2;
    qreal startX = qMax(0.0, m_xCounter - m_maxDisplayPoints);

    for (int i = 0; i < m_data1.size(); ++i) {
        points1.append(QPointF(startX + i, m_data1.at(i)));
        points2.append(QPointF(startX + i, m_data2.at(i)));
    }

    m_series1->replace(points1);
    m_series2->replace(points2);
    m_axisX->setRange(startX, startX + m_maxDisplayPoints);
}

void MyWave::resizeEvent(QResizeEvent *event)
{
    m_chartView->resize(event->size());
    QWidget::resizeEvent(event);
}

四、演示效果