Qt QChart，利用QChart繪制動態曲線

運行環境 ：

Qt Creator 4.2.1

Based on Qt 5.8.0 (MSVC 2015, 32 bit)

--------------------------------------------------------------------------------------

QtChartsTest.pro

這個文件中唯一需要添加的是

QT += charts

其他可以不看

#-------------------------------------------------
#
# Project created by QtCreator 2017-07-11T10:12:57
#
#-------------------------------------------------
QT       += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = QtChartsTest
TEMPLATE = app
# The following define makes your compiler emit warnings if you use
# any feature of Qt which as been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS
# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0
SOURCES += main.cpp\
        mainwindow.cpp
HEADERS  += mainwindow.h
FORMS    += mainwindow.ui
QT += charts

這個文件聲明了一個定時器的槽和一個獲得數據的方法

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
protected:
    void timerEvent(QTimerEvent *event) Q_DECL_OVERRIDE;
private:
    Ui::MainWindow *ui;
    double getData(double time);
};
#endif // MAINWINDOW_H

主程序中配置好Qchart，QLineSeries是用來存放數據。更新的工作放在定時器的槽中。其中

m_series->setUseOpenGL(true);//openGl 加速

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "QtCharts/QChart"
#include "QLineSeries"
#include "QValueAxis"
#include "QTimer"
#include "QTime"
#include "QList"
#include "qmath.h"
#include "QPointF"
#include "QDebug"
//#include <QtCharts/QChartGlobal>
#include "QChartView"
QT_CHARTS_USE_NAMESPACE
QChart *m_chart;
QLineSeries *m_series;
//QList<double> dataList;//存儲業務數據
int maxSize = 5000;
//QTimer updateTimer;
int timeId;
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),//默認初始化？
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    m_chart = new QChart;
    QChartView *chartView = new QChartView(m_chart);
//    v.setRubberBand(QChartView::HorizontalRubberBand);
    chartView->setRubberBand(QChartView::RectangleRubberBand);
//    chartView->setRubberBand();
    m_series = new QLineSeries;
    m_chart->addSeries(m_series);
    for(int i=0;i<maxSize;++i){
       m_series->append(i,0);
    }
    m_series->setUseOpenGL(true);//openGl 加速
    qDebug()<<m_series->useOpenGL();
    QValueAxis *axisX = new QValueAxis;
    axisX->setRange(0,maxSize);
    axisX->setLabelFormat("%g");
    axisX->setTitleText("axisX");
    QValueAxis *axisY = new QValueAxis;
    axisY->setRange(-1.5,1.5);
    axisY->setTitleText("axisY");
    m_chart->setAxisX(axisX,m_series);
    m_chart->setAxisY(axisY,m_series);
    m_chart->legend()->hide();
    m_chart->setTitle("demo");
    QVBoxLayout *layout = ui->verticalLayout;
    layout->addWidget(chartView);
    timeId = startTimer(30);
}
double MainWindow::getData(double time){
    double s = qCos( time * M_PI * 2 ) ;
    return s;
}
void MainWindow::timerEvent(QTimerEvent *event){
    if(event->timerId()==timeId){//定時器到時間,//模擬數據填充
        static QTime dataTime(QTime::currentTime());
        long int eltime = dataTime.elapsed();
        static int lastpointtime = 0;
        int size = (eltime - lastpointtime);//數據個數
        qDebug()<<"size-->"<<size;
        if(isVisible()){
            QVector<QPointF> oldPoints = m_series->pointsVector();//Returns the points in the series as a vector
            QVector<QPointF> points;
            for(int i=size;i<oldPoints.count();++i){
                points.append(QPointF(i-size ,oldPoints.at(i).y()));//替換數據用
            }
            qint64 sizePoints = points.count();
            for(int k=0;k<size;++k){
                points.append(QPointF(k+sizePoints,getData((((double)lastpointtime+k+1)/1000))));
            }
            m_series->replace(points);
            lastpointtime = eltime;
       }
    }
}
MainWindow::~MainWindow()
{
    delete ui;
}

main.cpp

沒什么好說的

#include "mainwindow.h"
#include <QApplication>
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

這個里自己放一個vertical Layout

這只是我根據別人的程序寫的簡單demo，有問題歡迎討論。

demo文件：

鏈接：http://pan.baidu.com/s/1cKXtIQ 密碼：5sm2