178 折线图-柱形图-饼状图

1.折线图

1、QChart 类继承自 QGraphicsWidget，用于管理图表、图例和轴。
2、QValueAxis 类专门用来自定义图表中 X 和 Y 坐标轴。
3、QLineSeries 类专门用于折线图（曲线）的形式展示数据

//.pro
QT += core  gui charts#ifndef WIDGET_H
#define WIDGET_H#include <QWidget>
#include <QtCharts>
QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACEclass Widget : public QWidget
{Q_OBJECTpublic:Widget(QWidget *parent = nullptr);~Widget();//自定义函数实现折线图void myselfLineSeriesFunc();private:Ui::Widget *ui;
};
#endif // WIDGET_H//.c#include "widget.h"
#include "ui_widget.h"Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget)
{ui->setupUi(this);//调用此函数myselfLineSeriesFunc();
}Widget::~Widget()
{delete ui;
}void Widget::myselfLineSeriesFunc()
{//实例化图表QChart对象QChart * chart = new QChart;chart->setTitle("全球各国军事增长折线图");ui->graphicsView->setChart(chart);//设置X坐标QValueAxis * axisX = new QValueAxis;axisX->setTitleText("年份");axisX->setRange(2017,2021);//设置范围//axisX->setTickCount(6);//这只刻度个数axisX->setLineVisible(true);axisX->setGridLineVisible(true);//设置网格线是否可见//设置Y坐标QValueAxis * axisY = new QValueAxis;axisY->setTitleText("军事(万亿:美元)");axisY->setRange(2000,10000);//设置范围axisY->setTickCount(5);//这只刻度个数axisY->setLineVisible(true);axisY->setGridLineVisible(true);//设置网格线是否可见//绘制折线图，设置序列QLineSeries * sris1 =new QLineSeries;sris1->setName("中国");sris1->setColor(QColor(255,0,0));//设置序列颜色值//添加数据点到序列sris1->append(2017,5000);sris1->append(2018,6500);sris1->append(2019,4900);sris1->append(2020,8000);sris1->append(2021,8900);sris1->append(2022,9000);QLineSeries * sris2 =new QLineSeries;sris2->setName("美国");sris2->setColor(QColor(0,255,0));//设置序列颜色值//添加数据点到序列sris2->append(2017,6500);sris2->append(2018,7300);sris2->append(2019,7500);sris2->append(2020,8000);sris2->append(2021,8700);sris2->append(2022,9200);QLineSeries * sris3 =new QLineSeries;sris3->setName("俄罗斯");sris3->setColor(QColor(0,0,255));//设置序列颜色值//添加数据点到序列sris3->append(2017,4000);sris3->append(2018,8000);sris3->append(2019,7900);sris3->append(2020,8000);sris3->append(2021,8200);sris3->append(2022,9500);//为QChart添加序列chart->addSeries(sris1);chart->addSeries(sris2);chart->addSeries(sris3);//将序列设置到坐标轴上chart->setAxisX(axisX,sris1);chart->setAxisY(axisY,sris1);chart->setAxisX(axisX,sris2);chart->setAxisY(axisY,sris2);chart->setAxisX(axisX,sris3);chart->setAxisY(axisY,sris3);}

2.柱形图

1、QBarSet 类专用于条形图中的一组条形集。
2、QStackedBarSeries 类在 QChart 中用于创建堆积柱状图。
3、QBarCategoryAxis 类用于提供柱状图的轴。

//.pro
QT       += charts#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>
#include <QChart>
using namespace QtCharts;#include <QBarSet>
#include <QBarSeries>
#include <QBarCategoryAxis>
#include <QChartView>
#include <QValueAxis>
#include <QStackedBarSeries>QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACEclass MainWindow : public QMainWindow
{Q_OBJECTpublic:MainWindow(QWidget *parent = nullptr);~MainWindow();private:Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H//.c#include "mainwindow.h"#include <QApplication>int main(int argc, char *argv[])
{QApplication a(argc, argv);//创建条形集对象QBarSet * ba = new QBarSet("bar");*ba<<560<<710<<599<<688<<701;QStackedBarSeries *sris = new QStackedBarSeries();sris->append(ba);QChart * chart = new QChart();chart->addSeries(sris);chart->setTitle("某某学校实验班高考成绩分数");QStringList strlist = {"小王","小李","小吴","小张","小赵"};//通过QBarCategoryAxis类将类型添加到图表的轴QBarCategoryAxis * axisX = new QBarCategoryAxis();axisX->append(strlist);axisX->setTitleText("考生姓名");chart->addAxis(axisX,Qt::AlignBottom);//通过QBarCategoryAxis类将类型添加到图表的轴QValueAxis * axisY = new QValueAxis();axisY->setRange(0,750);axisY->setTitleText("高考总分阶梯");chart->addAxis(axisY,Qt::AlignLeft);sris->attachAxis(axisX);sris->attachAxis(axisY);//图例展示chart->legend()->setVisible(false);//设置绘图区与图表边界chart->legend()->setAlignment(Qt::AlignBottom);//将图标显示到图表视图区QChartView * chartView = new QChartView(chart);MainWindow w;w.setWindowTitle("高考成绩--柱状图表展示");w.setCentralWidget(chartView);w.resize(800,500);w.show();return a.exec();
}

3.饼状图

1、QPieSeries 类专用于提供饼图形状。
2、QPieSlice 类设置颜色。

//.pro
QT       += charts#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>
#include <QChart>
#include <QtCharts/QPieSeries>
#include <QtCharts/QPieSlice>
#include <QtCharts/QChartView>
using namespace QtCharts;
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACEclass MainWindow : public QMainWindow
{Q_OBJECTpublic:MainWindow(QWidget *parent = nullptr);~MainWindow();private:Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H//.cpp#include "mainwindow.h"#include <QApplication>int main(int argc, char *argv[])
{QApplication a(argc, argv);//创建饼状图对象QPieSeries *sris =  new  QPieSeries();//新建比例sris->append("70分以下:30%",30);sris->append("70分-85分:40%",40);sris->append("86分-99分:25%",25);sris->append("100分:5%",5);sris->setLabelsVisible();//设置标签属性，可见QPieSlice * sred = sris->slices().at(0);QPieSlice * sgree = sris->slices().at(1);QPieSlice * sblue = sris->slices().at(2);QPieSlice * sblack = sris->slices().at(3);sred->setColor(QColor(255,0,0,255));sgree->setColor(QColor(0,255,0,255));sblue->setColor(QColor(0,0,255,255));sblack->setColor(QColor(0,0,0,255));QChart * chart = new QChart();chart->addSeries(sris);chart->setTitle("饼图形状--班级考试百分制");QChartView *chartview = new QChartView(chart);MainWindow w;w.setCentralWidget(chartview);w.resize(600,600);w.show();return a.exec();
}