Create class

[nymar]

Hi

i'm a begginer and i want to learn how to create my own class and use it in another project later.
i did like this and it didn't work i create new project in which i made my new class for exemple "mywindow" ,i compile it and it works. now i open another project and i call it #include<mywindow> i got an error "#include<mywindow> no such file or directory "

[BelenMuñoz]

The old class has to be in the same folder, if it's not there, you'll have to add the path in the .pro file.
I hope it helps.

[qxoz]

Hi all what i can advice to you for now is start learn C++ language and Qt.
For C++ language:
"http://www.cplusplus.com/doc/tutorial/":http://www.cplusplus.com/doc/tutorial/
or many other free resources(use google)
for Qt:
C++ GUI Programming with Qt 4 – By Jasmin Blanchette, Mark Summerfield
"doc":http://qt-project.org/doc/[qt-project.org]
best one and free videos: "http://voidrealms.com/tutorials.aspx?filter=qt":http://voidrealms.com/tutorials.aspx?filter=qt

[nymar]

just tell me about the syntax of the path for ex
i have folder in desktop called my project in which i have 2 project one is my class "mywindow" the second is the new project
so if i follow u i should write the path in .pro file but how

[nymar]

qxoz i'm following a tuto of c++ and Qt
look what he did
First he made a project FenPrincipale
header
@
#ifndef FENPRINCIPALE_H
#define FENPRINCIPALE_H
#include <QtGui>
#include <QMainWindow>
class FenPrincipale : public QMainWindow
{
public:
FenPrincipale();
private:
};

#endif // FENPRINCIPALE_H

main
#include <QApplication>
#include <QtGui>
#include <QMainWindow>
#include "FenPrincipale.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
FenPrincipale fenetre;
fenetre.show();
return app.exec();
}
@
.cpp
@
#include "FenPrincipale.h"
FenPrincipale::FenPrincipale()
{
}
@
it works fine for me, but later in the tuto he make a second project
with the following main
@
#include <QApplication>
#include <QtGui>
#include "FenPrincipale.h"
FenPrincipale::FenPrincipale()
{
QVBoxLayout *layout = new QVBoxLayout;
QDirModel *modele = new QDirModel;
QTreeView *vue = new QTreeView;
vue->setModel(modele);
layout->addWidget(vue);
setLayout(layout);
}
@

i made new project and paste FenPrincipale.h in the same folder with the new project but this is what i got
@
C:\Qt\Qt5.0.1\5.0.1\mingw47_32\lib\libqtmaind.a(qtmain_win.o):-1: In function `WinMain@16':

Q:\qt5_workdir\w\s\qtbase\src\winmain\qtmain_win.cpp:131: erreur : undefined reference to `qMain(int, char**)'

collect2.exe:-1: erreur : error: ld returned 1 exit status
@

Edit: please spend a little effort to make your post readable. Using @ tags around code sections already helps a lot, but properly indented code would be even better; Andre

[qxoz]

Can you give a link to that tutorial or post your project on some file hosting? So i can understand what you doing wrong and help.
and please edit your previos post use @ tag for code.

[nymar]

it's long 600 pages u need to follow it from begin i don't think it's a good idea but u can help me by explaining step by step how to create a class and call it in another project i would appreciate it

[qxoz]

Sure. Lets see your code. You say
[quote author="nymar" date="1361958556"]
it works fine for me, but later in the tuto he make a second project
with the following main [/quote]

Try change your class as:
.h
@#ifndef FENPRINCIPALE_H
#define FENPRINCIPALE_H
#include <QtGui>
#include <QMainWindow>

class FenPrincipale : public QMainWindow
{
Q_OBJECT
public:
explicit FenPrincipale(QWidget *parent = 0);
FenPrincipale();
private:
QVBoxLayout *layout;
QDirModel *modele;
QTreeView *vue;
};

#endif // FENPRINCIPALE_H@
.cpp
@FenPrincipale::FenPrincipale(QWidget *parent) :
QMainWindow(parent)
{
layout = new QVBoxLayout;
modele = new QDirModel;
vue = new QTreeView;
vue->setModel(modele);
layout->addWidget(vue);
setLayout(layout);
}@

leave main() as in first project
@#include <QApplication>
#include <QtGui>
#include <QMainWindow>
#include "FenPrincipale.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
FenPrincipale fenetre;
fenetre.show();
return app.exec();
}@

Try this and tell me what you got.

[nymar]

i'm slow i know it but i have 2 projects now
1-FenPrincipale contains (FenPrincipale.h +main.cpp+ FenPrincipale.cpp)

2-test contains (main.cpp + FenPrincipale.h (which i imported from the first project))
and if i'm not wrong ur making a new project in which u define a new class and u use it inside the same project isn't it ?

[qxoz]

Well you can also use existing class in many projects. It's doesn't matter you create or include new class.