QChartView or QGraphicScene

SGaist

Hi

Did you add QT += charts to your .pro file ?

Zhitoune

Thanks for your reply.
Yes i did , but it still doesn't work....
here is my .pro just in case :

#-------------------------------------------------
#
# Project created by QtCreator 2017-07-27T14:27:37
#
#-------------------------------------------------

QT       += core gui \
       charts


greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = aoFcs
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\
   tools.cpp \
   chartWidget.cpp \
   mainWindow.cpp \
   settingWidget.cpp

HEADERS  += \
   tools.h \
   chartWidget.h \
   mainWindow.h \
   settingWidget.h

SGaist

And re-ran qmake after adding the module ?

Zhitoune

It still doesn't work.
I compared qmake and make instruction of my project and a qt example that works and they are striclty the same apart from the directory adress.

Zhitoune

So apparently declaring

#include <QtCharts/QChartGlobal>

was not enough

I had to declare :

#include <QtCharts/QChartGlobal>
#include <QtCharts/QChart>
#include <QtCharts/QChartView>
#include <QtCharts/QLineSeries>
#include <QtCharts/QScatterSeries>

Don't ask me why it works in the examples and not in my project...
Thanks for you help!

SGaist

What example are you referring to ?

Zhitoune

it was themedWidget

SGaist

Where did you get that example ?

Zhitoune

in qt creator.

SGaist

Can you give the exact name please ?

JKSH

@Zhitoune said in QChartView or QGraphicScene:

So apparently declaring

#include <QtCharts/QChartGlobal>

was not enough

I had to declare :

#include <QtCharts/QChartGlobal>
#include <QtCharts/QChart>
#include <QtCharts/QChartView>
#include <QtCharts/QLineSeries>
#include <QtCharts/QScatterSeries>

There are two step you should take to do this correctly.

First, use Forward Declarations in your header:

class QChart;
class QChartView;
class QLineSeries;
class QScatterSeries;

You need the forward declarations because your header contains the pointers QChart*, QChartView*, QLineSeries*, and QScatterSeries*.

Second, include the relevant headers in your .cpp file:

#include <QtCharts/QChart>
#include <QtCharts/QChartView>
#include <QtCharts/QLineSeries>
#include <QtCharts/QScatterSeries>

// OR, even better:
#include <QChart>
#include <QChartView>
#include <QLineSeries>
#include <QScatterSeries>

Don't ask me why it works in the examples and not in my project...

One reason is because the example does not refer to QLineSeries or QScatterSeries in the header: That's why the example doesn't need to forward-declare these two classes.

Note that the example:

Forward-declares QChart and QChartView in the header file: https://doc.qt.io/qt-5/qtcharts-chartthemes-themewidget-h.html
#includes lots of chart-related classes in the .cpp file: https://doc.qt.io/qt-5/qtcharts-chartthemes-themewidget-cpp.html

Finally, you can get rid of QT_CHARTS_BEGIN_NAMESPACE and QT_CHARTS_END_NAMESPACE from your code. These macros are not strictly necessary.