绘制温度曲线图；QChart，

.pro

QT       += core gui charts

widget.h

#include "widget.h"
#include "ui_widget.h"
#include <QChart>
#include <QChartView>
#include <QValueAxis>
#include <QLineSeries>
#include <QSplineSeries>
#include <QPen>

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    this->setLayout(ui->verticalLayout);
    //1创建图表视图；这里直接在ui中创建了
    //QChartView *chartView = new QChartView();
    //2、创建图表；
    QChart *chart = new QChart();

    //3、创建坐标轴；
    QValueAxis *valueAxisX = new QValueAxis();
    QValueAxis *valueAxisY = new QValueAxis();

    //4、设置坐标轴范围；
    valueAxisX->setRange(0,5000);
    valueAxisY->setRange(0,110);

    //5、设置坐标轴标题和显示格式；
    valueAxisX->setTitleText("时间/ms");
    valueAxisY->setTitleText("温度/℃");
    valueAxisX->setLabelFormat("%d");
    valueAxisY->setLabelFormat("%.2f");
    //设置坐标轴的精度；
    valueAxisX->setTickCount(11);
    valueAxisY->setTickCount(11);

    //6、图表添加坐标轴；
    chart->addAxis(valueAxisX,Qt::AlignBottom);
    chart->addAxis(valueAxisY,Qt::AlignLeft);

    //7、设置图表的标题以及图例显示；
    chart->setTitle("温度变化图");
    chart->legend()->setVisible(false);

    //8、创建曲线；
    QSplineSeries *splineSeres = new QSplineSeries;
    splineSeres->append(0,50);
    splineSeres->append(1000,100);
    splineSeres->append(2000,80);
    splineSeres->append(3000,40);
    splineSeres->append(4000,60);
    splineSeres->append(5000,50);

    //9、设置曲线的颜色；
    QPen pen(QColor(0xff5566));
    pen.setWidth(5);
    splineSeres->setPen(pen);

    //10、图表添加线；
    chart->addSeries(splineSeres);

    //11、将曲线和坐标轴联系起来；
    splineSeres->attachAxis(valueAxisX);
    splineSeres->attachAxis(valueAxisY);

    //12、将图表放置在图表视图显示出来；
    ui->chartView->setChart(chart);

}

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

效果：