Qt（十三）QChart绘制折线图

Qt Charts基于Qt的Graphics View其核心组件是架构QChartView 和 QChart

• QChartView显示图标的视图是基类QGraphicsView
• QChart的基类是QGraphicsltem

类继承关系： 创建项目：.pro添加到文件中：QT = charts 代码如下：其他文件未修改，只修改代码mainwindow.cpp在文件中进行。 mainwindow.cpp

#include "mainwindow.h" #include "ui_mainwindow.h" #include <QChartView> #include <QLineSeries> #include <QValueAxis> #include <QtMath> QT_CHARTS_USE_NAMESPACE  MainWindow::MainWindow(QWidget *parent)     : QMainWindow(parent)     , ui(new Ui::MainWindow) { 
             ui->setupUi(this);     setWindowTitle("QChart简单绘图");      //创建图表框架     QChartView* cview = new QChartView(this);     QChart* chart = new QChart();     chart->setTitle("简单函数曲线");      cview->setChart(chart);     setCentralWidget(cview);

    //创建折现序列
    QLineSeries* seriesS = new QLineSeries;
    QLineSeries* seriesC = new QLineSeries;
    seriesS->setName("Sinθ");
    seriesC->setName("Cosθ");
    chart->addSeries(seriesS);
    chart->addSeries(seriesC);

    //添加数据绘制
    qreal y0,y1,t=0,intv=0.1;
    size_t count=100;
    for (size_t i=0;i<count;i++) { 
        
        y0 = qSin(t);
        y1 = qCos(t);
        seriesS->append(t,y0);
        seriesC->append(t,y1);
        t += intv;
    }

    //创建坐标轴
    QValueAxis* axisX = new QValueAxis;
    axisX->setRange(0,10);
    chart->setAxisX(axisX,seriesS);
    chart->setAxisX(axisX,seriesC);

    QValueAxis* axisY = new QValueAxis;
    axisY->setRange(-1, 1);
    chart->setAxisY(axisY,seriesS);
    chart->setAxisY(axisY,seriesC);

}

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

数据序列类继承关系 坐标类继承关系

初步UI设计

新建DialogPen类继承QDialog：

#ifndef DIALOGPEN_H
#define DIALOGPEN_H

#include <QDialog>
#include <QColorDialog>
#include <QPen>
#include <QPalette>

namespace Ui { 
        
class DialogPen;
}

class DialogPen : public QDialog
{ 
        
    Q_OBJECT

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

    QPen getpen();
    static QPen getPen(QPen initPen, bool &ok);
    void setPen(const QPen &pen);

private slots:
    void on_pushButton_clicked();

private:
    QPen m_pen;
    Ui::DialogPen *ui;
};

#endif // DIALOGPEN_H

#include "dialogpen.h"
#include "ui_dialogpen.h"
#include <QString>


DialogPen::DialogPen(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::DialogPen)
{ 
        
    ui->setupUi(this);
    ui->comboBox->clear();
    ui->comboBox->addItem("NoPen",0);
    ui->comboBox->addItem("SolidLine",1);
    ui->comboBox->addItem("DashLine",2);
    ui->comboBox->addItem("DotLine",3);
    ui->comboBox->addItem("DashDotLine",4);
    ui->comboBox->addItem("DashDotDotLine",5);
    ui->comboBox->addItem("CustomDashLine",6);
    ui->comboBox->setCurrentIndex(0);
}

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

void DialogPen::on_pushButton_clicked()
{ 
        
    QColor color = m_pen.color();
    QColorDialog::getColor(color);
    if(color.isValid()){ 
        
        QString str = QString::asprintf("background-color: rgb(%d,%d,%d)",color.red(),color.green(),color.blue());
        ui->btnColor->setStyleSheet(str);
    }

}

QPen DialogPen::getpen()
{ 
        
    m_pen.setStyle(Qt::PenStyle(ui->comboBox->currentIndex()));
    m_pen.setWidth(ui->spinBox->value());
    QColor color = ui->btnColor->palette().color(QPalette::Button);
    m_pen.setColor(color);
    return m_pen;
}

QPen DialogPen::getPen(QPen initPen, bool &ok)
{ 
        
    DialogPen* dlg = new DialogPen;
    QPen pen;
    dlg->setPen(initPen);
    int ret = dlg->exec();
    if (ret == QDialog::Accepted){ 
        
        pen = dlg->getpen();
        ok = true;
    }else { 
        
        pen = initPen;
        ok = false;
    }
    delete dlg;
    return pen;
}

void DialogPen::setPen(const QPen &pen)
{ 
        
    m_pen = pen;
    ui->spinBox->setValue(pen.width());
    int i = static_cast<int>(pen.style());
    ui->comboBox->setCurrentIndex(i);
    ui->btnColor->setAutoFillBackground(true);
    QColor color = pen.color();
    QString str = QString::asprintf("background-color: rgb(%d,%d,%d)",color.red(),color.green(),color.blue());
    ui->btnColor->setStyleSheet(str);
}

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QChartView>
#include <QtCharts>
#include <QColor>
#include <QLineSeries>
#include <QValueAxis>
#include <QtMath>
#include <QTime>
#include <QChart>
#include <QFontDialog>
#include "dialogpen.h"

QT_CHARTS_USE_NAMESPACE

QT_BEGIN_NAMESPACE
namespace Ui { 
         class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{ 
        
    Q_OBJECT

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

private slots:
    void on_actZoomOut_triggered();

    void on_actZoomIn_triggered();

    void on_actReset_triggered();

    void on_actFlush_triggered();

    void on_btn_set_clicked();

    void on_btn_titleFont_clicked();

    void on_rBtn_Up_clicked();

    void on_rBtn_Down_clicked();

    void on_rBtn_Left_clicked();

    void on_rBtn_Right_clicked();

    void on_checkBox_legend_clicked(bool checked);

    void on_checkBox_legendBG_clicked(bool checked);

    void on_pBtn_Font_clicked();

    void on_pBtn_legendcolor_clicked();

    void on_pBtn_setMargin_clicked();

    void on_comboBox_motion_currentIndexChanged(int index);

    void on_comboBox_theme_currentIndexChanged(int index);

    void on_sin_curve_clicked();

    void on_cos_curve_clicked();

    void on_pBtn_name_clicked();

    void on_checkBox_curve_clicked(bool checked);

    void on_checkBox_data_clicked(bool checked);

    void on_pBtn_color_clicked();

    void on_pBtn_pen_clicked();

    void on_horizontalSlider_valueChanged(int value);

    void on_checkBox_pointLableVisible_clicked(bool checked);

    void on_pushButton_13_clicked();

    void on_pushButton_12_clicked();

    void on_rBtn_Y_clicked();

    void on_rBtn_XY_clicked();

    void on_rBtn_XAxies_clicked();

    void on_rBtn_YAxies_clicked();

    void on_Axis_isVisible_clicked(bool checked);

    void on_Axis_range_clicked();

    void on_Axis_setTitle_clicked();

    void on_Axis_titleIsVisible_clicked(bool checked);

    void on_pBtn_style_clicked();

    void on_pBtn_Fontcolor_clicked();

    void on_pBtn_setFont_clicked();

    void on_chk_scaleIsVisible_clicked(bool checked);

    void on_chk_gridLineVisible_clicked(bool checked);

    void on_pBtn_Fontcolor_2_clicked();

    void on_pBtn_Fontcolor_3_clicked();

    void on_spinBox_Tickcount_valueChanged(int arg1);

    void on_spinBox_minorTickcount_valueChanged(int arg1);

    void on_chk_TickLineIsVisible_clicked(bool checked);

    void on_pBtn_Fontcolor_5_clicked();

    void on_pBtn_Fontcolor_4_clicked();

    void on_pBtn_Fontcolor_7_clicked();

    void on_pBtn_Fontcolor_6_clicked();

    void on_chk_MinorTickLineIsVisible_clicked(bool checked);

private:
    Ui::MainWindow *ui;
    void createChart();
    QLineSeries* curSeries;
    QValueAxis* curAxis;

    void prepareData();
    void updateFromChart();
};
#endif // MAINWINDOW_H

mainwindow.cpp