《Qt5+QtChart绘制折线图（QLineSeries类）》

QtChart可用于绘制折线图，在折线图中，数据点通过直线连接。要想绘制折线图至少要用到QLineSeries、QChart、QChartView这三个类。QLineSeries类用于创建有由一系列点组成的折线；QChart类用于控制整个图表界面的设置，例如坐标轴、主题、背景色、标题、legend等；QChartView类用于显示图表，将图表显示到QWidget或者QGraphicsWidget上。

 

 

代码示例

---

打开Qt，新建一个Qt Widgets Application项目，使用QtChart绘制图表需要在pro文件中添加QT += charts，并且还需要在编写代码文件中添加名称空间QT_CHARTS_USE_NAMESPACE，一般放在头文件的后面，Pro文件如下所示：

#-------------------------------------------------
#
# Project created by QtCreator 2018-12-10T12:52:02
#
#-------------------------------------------------
QT       += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
QT += charts
TARGET = LineChart
TEMPLATE = app
# The following define makes your compiler emit warnings if you use
# any feature of Qt which has 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

然后在main.cpp文件中添加如下代码，代码已经注释的很详细了：

#include "mainwindow.h"
#include <QApplication>
#include <QtCharts/QChartView>//显示图表
#include <QtCharts/QLineSeries>//线系列
#include <QDoubleSpinBox>

QT_CHARTS_USE_NAMESPACE//QtChart名空间

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;

    QList<QLineSeries *> m_series;
    QLineSeries *series1 = new QLineSeries();//实例化一个QLineSeries对象
    QLineSeries *series2 = new QLineSeries();//实例化一个QLineSeries对象
    m_series.append(series1);
    m_series.append(series2);
    //设置线条名称
    series1->setName(QString("line " + QString::number(1)));
    series2->setName(QString("line " + QString::number(2)));
    //series->setName(QString("line " + QString::number(m_series.count())));
    //设置线条颜色，如果不设置会给默认颜色
    series1->setColor(QColor(255,0,255));
    series2->setColor(QColor(0,255,255));
    //series1->setBrush(QColor(255,0,255));
    //series1->setPen(QColor(255,0,255));
    //设置是否线条可视
    series1->setVisible(true);
    series2->setVisible(true);
    //点标签是否可视
    series1->setPointLabelsVisible(true);
    series2->setPointLabelsVisible(true);
    //点标签颜色
    series1->setPointLabelsColor(QColor(255,255,255));
    series2->setPointLabelsColor(QColor(255,255,255));
    //点标签字体
    series1->setPointLabelsFont(QFont("微软雅黑"));
    series2->setPointLabelsFont(QFont("微软雅黑"));
    //设置点标签显示格式
    series1->setPointLabelsFormat("(@xPoint,@yPoint)");
    series2->setPointLabelsFormat("(@xPoint,@yPoint)");
    //是否切割边缘点标签，默认为true
    series1->setPointLabelsClipping(false);
    series2->setPointLabelsClipping(true);
    //设置点标签是否可视
    series1->setPointsVisible(true);
    series2->setPointsVisible(true);

    //添加坐标点
    series1->append(0, 6);
    series1->append(2, 4);
    series1->append(3, 8);
    series1->append(7, 4);
    series1->append(10, 5);
    *series1 << QPointF(11, 1) << QPointF(13, 3) << QPointF(17, 6) << QPointF(18, 3) << QPointF(20, 2);

    series2->append(0, 8);
    series2->append(2, 5);
    series2->append(3, 3);
    series2->append(7, 9);
    series2->append(10, 2);
    *series2 << QPointF(11, 3) << QPointF(13, 8) << QPointF(17, 2) << QPointF(18, 5) << QPointF(20, 7);


    QChart *chart = new QChart();
    chart->setTheme(QChart::ChartThemeBlueCerulean);//设置系统主题
    chart->setAnimationOptions(QChart::AllAnimations);//设置启用或禁用动画
    //chart->setBackgroundBrush(QBrush(QColor(170,170,255)));//设置背景色,主题和背景二选一
    //chart->setDropShadowEnabled(true);//是否背景阴影
    chart->setLocalizeNumbers(true);//数字是否本地化
    //chart->legend()->show();//legend是否显示，show和hide
    chart->addSeries(series1);//添加系列到QChart上
    chart->addSeries(series2);//添加系列到QChart上
    chart->createDefaultAxes();//创建默认轴
    chart->setTitle("Simple line chart example");//设置标题
    chart->setTitleBrush(QBrush(QColor(255,170,255)));//设置标题Brush
    chart->setTitleFont(QFont("微软雅黑"));//设置标题字体

    chart->legend()->setVisible(true);
    chart->legend()->setAlignment(Qt::AlignBottom);//底部对齐
    //chart->legend()->detachFromChart();
    chart->legend()->setBackgroundVisible(true);//设置背景是否可视
    //chart->legend()->setAutoFillBackground(true);//设置背景自动填充
    //chart->legend()->setColor(QColor(255,128,128,128));//设置颜色
    //chart->legend()->setContentsMargins(10,10,10,10);//设置边距left,top,right,bottom
    chart->legend()->setLabelColor(QColor(255,128,255));//设置标签颜色
    chart->legend()->setVisible(true);//设置是否可视
    //chart->legend()->setMaximumHeight(50);
    //chart->legend()->setMaximumWidth(120);
    //chart->legend()->setMaximumSize(10000);
    //chart->legend()->setGeometry(50,50,120,50);//设置几何位置x,y,w,h
    //chart->legend()->setBrush(QBrush(QColor(128,128,128,128)));
    //chart->legend()->setPen(QPen(QColor(192,192, 192,192)));
    chart->legend()->setBorderColor(QColor(255,255,170,185));//设置边框颜色
    QFont font = chart->legend()->font();
    font.setItalic(!font.italic());
    chart->legend()->setFont(font);//设置字体为斜体
    font.setPointSizeF(12);
    chart->legend()->setFont(font);//设置字体大小
    chart->legend()->setFont(QFont("微软雅黑"));//设置字体类型


    QChartView *chartView = new QChartView(chart);
    chartView->setRenderHint(QPainter::Antialiasing);

    w.setCentralWidget(chartView);
    w.resize(960, 720);
    w.show();

    return a.exec();
}

 

完整代码

---

优快云下载：https://download.youkuaiyun.com/download/mars_xiaolei/10840847

百度网盘链接：https://pan.baidu.com/s/1sYzagekYPpEz41cHRfctQg
提取码：ptui