Can I use "Promote to..." with Qwt?

[8Observer8]

Hello!

Sorry for my English in advance :)

I will have class "Graph" in the file "Graph.h". I want to have a widget which I can "Promote to ..." from Qt Designer, like in the picture:
10556

Must I inherit QwtPlot and QWidget? How to show the plot?


#ifndef GRAPH_H
#define GRAPH_H

#include <QWidget>
#include <qwt_plot.h>

class Graph : public QWidget, QwtPlot
{
public:
Graph()
{

}
};

#endif // GRAPH_H

[Uwe]

QwtPlot is already derived from QWidget ( your code above doesn't make much sense ) and you can do with it, what you can do with any other QWidget.

Note that you could also install the Qwt designer plugin to customize QwtPlot widgets from the designer or creator.

Uwe

[8Observer8]

Thank you! I will install plugin later

I cannot run my application. I receive this message in the "Application Output":


Starting D:\Qt\QwtExamples\0007_Line\build-Line-Desktop_Qt_5_3_1_MinGW_32bit-Debug\debug\Line.exe...
The program has unexpectedly finished.
D:\Qt\QwtExamples\0007_Line\build-Line-Desktop_Qt_5_3_1_MinGW_32bit-Debug\debug\Line.exe crashed




#ifndef GRAPH_H
#define GRAPH_H

#include <qwt_plot.h>

class Graph : public QwtPlot
{
public:
Graph( QWidget *widget = 0 ) :
QwtPlot( widget )
{

}
};

#endif // GRAPH_H

[8Observer8]

What must I show? I don't have more code in this project

[8Observer8]

Please, it is very important. How to show a graph?

[8Observer8]

Please, help me! This is my steps:

- I created a MainWindow application
- I added in the .pro file this code:

QWT_LOCATION = c:/Qwt-6.1.0
INCLUDEPATH += $${QWT_LOCATION}/include
LIBS = -L$${QWT_LOCATION}/lib \
-lqwtd

- I create the class "Plot":

Plot.h


#ifndef PLOT_H
#define PLOT_H

#include "qwt_plot.h"

class Plot : public QwtPlot
{
public:
Plot( QWidget *parent = 0 );
};

#endif // PLOT_H


Plot.cpp


#include "Plot.h"

Plot::Plot( QWidget *parent ) :
QwtPlot( parent )
{
}


- I opened the file "MainWindow.ui" and I put on the form the widget "Widget"
- I promoted the "Widget" to "Plot"
- I ran my application and received this message:

The program has unexpectedly finished.

[8Observer8]

This application doesn't work too:

VerySimple.pro



QT += widgets

INCLUDEPATH += "C:/Qwt-6.1.0/include"
LIBS += "C:/Qwt-6.1.0/lib/libqwtd.a"

SOURCES += \
main.cpp


main.cpp



#include <QApplication>
#include "qwt_plot.h"

int main( int argc, char *argv[] )
{
QApplication app( argc, argv );

QwtPlot plot;

plot.show();

app.exec();
}


Output:


The program has unexpectedly finished.


Added after 16 minutes:

I set breakpoint on the line "QApplication app( argc, argv );" I see:
10588

[wysota]

Please do a search on the forum for "0xc0000135".

[8Observer8]

I think it is because I built Qwt in Qt5.1.1 and I try to use it in Qt5.3.1