最近打算研究一下qt绘制曲线图，以前项目中绘制曲线图都是纯painter画的，查了一下才发现qt关于曲线的图绘制有自带的qchart，还有第三方的qcustomplot、qwt、echarts等等，先研究QChart，QChart是Qt5.7之后才有的并且安装qt的时候需要勾选对应组件，默认是不勾选的。根据qt官方例子和文档自己写了一个简单的demon。将表格中数据绘制成曲线图，然后可以选择控制曲线图的一些属性。

首先pro需要加入chart模块

QT       += charts

对应命名空间的引入

QT_CHARTS_USE_NAMESPACE

头文件：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QtCharts/QChartGlobal>
QT_BEGIN_NAMESPACE
namespace Ui {
class MainWindow;
}
QT_END_NAMESPACE
    QT_CHARTS_BEGIN_NAMESPACE
class QChartView;
class QChart;
class QLineSeries;
QT_CHARTS_END_NAMESPACE
    QT_CHARTS_USE_NAMESPACE
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
private slots:
    void on_paintBtn_clicked();
    void on_applyBtn_clicked();
    void on_lineColorPush_clicked();
    void on_legendColorBox_clicked();
private:
    Ui::MainWindow *ui;
    QChart *m_Chart;
    QChartView *m_ChartView;
    QLineSeries *m_Series;
};
#endif // MAINWINDOW_H

源文件：

 

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QtCharts/QChartView>
#include <QtCharts/QLineSeries>
#include <QValueAxis>
#include <QColorDialog>
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    m_Chart = new QChart();
    m_ChartView = new QChartView(m_Chart);
    QVBoxLayout *v = new QVBoxLayout;
    v->addWidget(m_ChartView);
    ui->chartWidget->setLayout(v);
    m_Chart->createDefaultAxes();
    // 添加线
    m_Series = new QLineSeries;
    m_Series->setName("line");
    m_Chart->addSeries(m_Series);
    // 坐标轴
    m_Chart->createDefaultAxes();
    m_Chart->axes(Qt::Horizontal).first()->setRange(0, 100);
    m_Chart->axes(Qt::Vertical).first()->setRange(0, 100);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_paintBtn_clicked()
{
    m_Series->clear();
    for (int i = 0; i < ui->dataTable->rowCount(); i++) {
        QTableWidgetItem *xitem = ui->dataTable->item(i, 0);
        QTableWidgetItem *yitem = ui->dataTable->item(i, 1);
        QPointF p;
        p.setX(xitem->text().toFloat());
        p.setY(yitem->text().toFloat());
        m_Series->append(p);
    }
}

void MainWindow::on_applyBtn_clicked()
{
    // 线条
    QPen pen;
    pen.setColor(ui->lineColorPush->property("color").toString());
    pen.setWidth(ui->lineWidthBox->value());
    pen.setStyle(Qt::PenStyle(ui->lineStyleCom->currentIndex()));
    m_Series->setPen(pen);
    // 坐标轴
    m_Chart->axes(Qt::Horizontal).first()->setRange(ui->xsBox->value(), ui->xeBox->value());
    m_Chart->axes(Qt::Vertical).first()->setRange(ui->ysBox->value(), ui->yeBox->value());
    m_Chart->axes(Qt::Horizontal).first()->setTitleText(ui->xNameLine->text());
    m_Chart->axes(Qt::Vertical).first()->setTitleText(ui->yNameLine->text());
    // 图例
    m_Chart->legend()->setVisible(ui->legendShowBox->isChecked());
    switch (ui->legendPosBox->currentIndex()) {
    case 0:
        m_Chart->legend()->setAlignment(Qt::AlignTop);
        break;
    case 1:
        m_Chart->legend()->setAlignment(Qt::AlignBottom);
        break;
    case 2:
        m_Chart->legend()->setAlignment(Qt::AlignLeft);
        break;
    case 3:
        m_Chart->legend()->setAlignment(Qt::AlignRight);
        break;
    default:
        break;
    }
    m_Chart->legend()->setLabelColor(ui->legendColorBox->property("color").toString());
}

void MainWindow::on_lineColorPush_clicked()
{
    QColorDialog dlg(this);
    if (dlg.exec() == QColorDialog::Accepted) {
        ui->lineColorPush->setProperty("color", dlg.selectedColor().name());
        ui->lineColorPush->setStyleSheet(QString("background-color: %1;").arg(dlg.selectedColor().
                                                                              name()));
    }
}

void MainWindow::on_legendColorBox_clicked()
{
    QColorDialog dlg(this);
    if (dlg.exec() == QColorDialog::Accepted) {
        ui->legendColorBox->setProperty("color", dlg.selectedColor().name());
        ui->legendColorBox->setStyleSheet(QString("background-color: %1;").arg(dlg.selectedColor().
                                                                               name()));
    }
}

运行效果：