Error initalizing QChart

[viniltc]

Hi all,

I tried to initialize a new QChart:

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QPainter>
#include <QtCharts/QAreaSeries>
#include <QtCharts/QChartView>
#include <QtCharts/QLineSeries>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    
        QLineSeries *series = new QLineSeries();

        series->append(0, 6);
        series->append(2, 4);
        series->append(3, 8);
        series->append(7, 4);
        series->append(10, 5);
        *series << QPointF(11, 1) << QPointF(13, 3) << QPointF(17, 6) << QPointF(18, 3) << QPointF(20, 2);
        
        QChart *chart = new QChart();  //---------->cant't initialize this
        chart->legend()->hide();
        chart->addSeries(series);
        chart->createDefaultAxes();
        chart->setTitle("Simple line chart example");

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



}

I get the following error:

mainwindow.cpp:70:9: error: unknown type name 'QChart'; did you mean 'QChar'?
qmetatype.h:1970:1: note: 'QChar' declared here
qmetatype.h:106:17: note: expanded from macro 'QT_FOR_EACH_STATIC_CORE_CLASS'

Could you please pointout where I'm doing wrong?

[JonB]

@viniltc
Always just look at the docs page. https://doc.qt.io/qt-5/qchart.html :

Header: #include <QChart>

[viniltc]

@JonB , Thankyou

I tried to initialize a QChart in the QMainWindow as follows:

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
            ui->setupUi(this);

            QLineSeries *series = new QLineSeries();
            series->append(0, 16);
            series->append(1, 25);
            series->append(2, 24);
            series->append(3, 19);
            series->append(4, 33);
            series->append(5, 25);
            series->append(6, 34);

            // Create chart, add data, hide legend, and add axis
            QChart *chart = new QChart();
            chart->legend()->hide();
            chart->addSeries(series);
            chart->createDefaultAxes();

            // Customize the title font
            QFont font;
            font.setPixelSize(18);
            chart->setTitleFont(font);
            chart->setTitleBrush(QBrush(Qt::black));
            chart->setTitle("Barry Bonds HRs as Pirate");

            // Change the line color and weight
            QPen pen(QRgb(0x000000));
            pen.setWidth(5);
            series->setPen(pen);

            chart->setAnimationOptions(QChart::AllAnimations);

            // Change the x axis categories
            QCategoryAxis *axisX = new QCategoryAxis();
            axisX->append("1986",0);
            axisX->append("1987",1);
            axisX->append("1988",2);
            axisX->append("1989",3);
            axisX->append("1990",4);
            axisX->append("1991",5);
            axisX->append("1992",6);
            chart->setAxisX(axisX, series);

            // Used to display the chart
            QChartView *chartView = new QChartView(chart);
            chartView->setRenderHint(QPainter::Antialiasing);


}

However , this is not showing anything , can you spot an issue?

[JonB]

@viniltc
Well, I've never used a QChart/QChartView(), but I imagine your QChartView() needs adding onto the main window somehow in order to appear?

QChartView *chartView = new QChartView(chart, this);

Does that make it visible? Then you can think about exactly how/where you want it added onto the main window properly, e.g. I imagine you'll want to put it into QMainWindow::setCentralWidget()?

[AndyJ]

@viniltc said in Error initalizing QChart:

mainwindow.cpp:70:9: error: unknown type name 'QChart';

The error states that QChart is an unknown type, so try including QtCharts after QPainter. See below.

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QPainter>
#include <QtCharts>

...

[SGaist]

Hi,

Are you missing QT += charts in your .pro file ?