Weird problem

[CactusPie]

I have the following code in file mainwindow.h:

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QMainWindow>
#include "logindialog.h"
 
namespace Ui {
class MainWindow;
}
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
private:
    Ui::MainWindow *ui; 
    LoginDialog *logindialog;
 
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
 
private slots:
    void ALogin_Clicked();
    void LoginDialog_Destroyed();
 
};
 
#endif // MAINWINDOW_H

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "logindialog.h"

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT
    
private:
    Ui::MainWindow *ui; 
    LoginDialog *logindialog;
    
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
    
private slots:
    void ALogin_Clicked();
    void LoginDialog_Destroyed();
    
};

#endif // MAINWINDOW_H

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Other related files:
logindialog.cpp
logindialog.h
mainwindow.cpp

Everything works fine, until I put ANY changes into logindialog.cpp file. When I do, I get the following error in line 17:

c:\users\mati\komunikator_klient_da_ze\mainwindow.h:17: błąd:C2143: syntax error : missing ';' before '*'
c:\users\mati\komunikator_klient_da_ze\mainwindow.h:17: błąd:C4430: missing type specifier - int assumed. Note: C++ does not support default-int
c:\users\mati\komunikator_klient_da_ze\mainwindow.h:17: błąd:C4430: missing type specifier - int assumed. Note: C++ does not support default-int

c:\users\mati\komunikator_klient_da_ze\mainwindow.h:17: błąd:C2143: syntax error : missing ';' before '*'
c:\users\mati\komunikator_klient_da_ze\mainwindow.h:17: błąd:C4430: missing type specifier - int assumed. Note: C++ does not support default-int
c:\users\mati\komunikator_klient_da_ze\mainwindow.h:17: błąd:C4430: missing type specifier - int assumed. Note: C++ does not support default-int

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The problem can easily be fixed, by removing line 17, recompliling the project (which gives even more errors) and then putting that line back. Everything will work fine, until I change logindialog.cpp again.
While it doesn't make it impossible to continue the project, it makes it very annoying...
The IDE I use is QtCreator 2.4.1

Could someone please help me?

[amleto]

I don't know why you get that error. I have not experienced it before. I think this will help, though:

In mainwindow.h dont use

#include "LoginDialog.h"

use

class LoginDialog;


use #include in the cpp

[CactusPie]

Well, I'll be. Looks like that fixed the problem. I was almost certain that this problem will be too odd for anyone to know how to fix it Thanks a lot!!!