Expected class-name before '{' token

[imagiro1]

I've working on my first project and I've hit a speed bump. When building, I get this error message. Expected class-name before '{' token in mainwindow.h line 8.

Here is mainwindow.h:

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include "ui_mainwindow.h"
 
 
class MainWindow : public QWidget, private Ui::MainWindowDLG
{
    Q_OBJECT
 
public:
  MainWindow(QWidget *parent = 0);
 
public slots:
 void display_pic();
 
};
 
#endif

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include "ui_mainwindow.h"


class MainWindow : public QWidget, private Ui::MainWindowDLG
{
    Q_OBJECT

public:
  MainWindow(QWidget *parent = 0);

public slots:
 void display_pic();

};

#endif

To copy to clipboard, switch view to plain text mode 

I know it's got to be something simple I am overlooking. Thanks in advance.

[spirit]

add #include <QWidget> in this file, e.g.

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QWidget>
#include "ui_mainwindow.h"
...

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QWidget>
#include "ui_mainwindow.h"
...

To copy to clipboard, switch view to plain text mode 

[imagiro1]

Tried it, same result.

[spirit]

attach all sources.

[imagiro1]

Attached #include <QWidget> too all other files main.cpp, mainwindow.cpp, and mainwindow.h. I think that is what you wanted me to try. Still get the same error message.

[spirit]

no, I was asking you to upload your sources, that I can try to compile your project by myself.

[imagiro1]

Sorry. Here we go...

main.cpp

#include <QApplication>
#include "mainwindow.h"
 
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MainWindow *dialog = new MainWindow;
 
    dialog->show();
    return app.exec();
}

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

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MainWindow *dialog = new MainWindow;

    dialog->show();
    return app.exec();
}

To copy to clipboard, switch view to plain text mode 

mainwindow.cpp

#include "mainwindow.h"
#include <QtGui> 
#include <QPixmap>
 
 
MainWindow::MainWindow(QWidget *parent)
{
    setupUi(this);
    connect( pushButton_display, SIGNAL( clicked() ), this, SLOT( display_pic() ) );
 
}
 
void MainWindow::display_pic()
{
    QPixmap pixmap("Dima.jpg");
 
    label_image->setPixmap(pixmap);
}

#include "mainwindow.h"
#include <QtGui> 
#include <QPixmap>


MainWindow::MainWindow(QWidget *parent)
{
    setupUi(this);
    connect( pushButton_display, SIGNAL( clicked() ), this, SLOT( display_pic() ) );

}

void MainWindow::display_pic()
{
    QPixmap pixmap("Dima.jpg");

    label_image->setPixmap(pixmap);
}

To copy to clipboard, switch view to plain text mode 

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QWidget>
#include "ui_mainwindow.h"
 
 
class MainWindow : public QWidget, private Ui::MainWindowDLG
{
    Q_OBJECT
 
public:
  MainWindow(QWidget *parent = 0);
 
public slots:
 void display_pic();
 
};
 
#endif

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QWidget>
#include "ui_mainwindow.h"


class MainWindow : public QWidget, private Ui::MainWindowDLG
{
    Q_OBJECT

public:
  MainWindow(QWidget *parent = 0);

public slots:
 void display_pic();

};

#endif

To copy to clipboard, switch view to plain text mode 

ui_mainwindow.h

/********************************************************************************
** Form generated from reading ui file 'mainwindow.ui'
**
** Created: Mon Jun 15 22:04:49 2009
**      by: Qt User Interface Compiler version 4.5.1
**
** WARNING! All changes made in this file will be lost when recompiling ui file!
********************************************************************************/
 
#ifndef UI_MAINWINDOW_H
#define UI_MAINWINDOW_H
 
#include <QtCore/QVariant>
#include <QtGui/QAction>
#include <QtGui/QApplication>
#include <QtGui/QButtonGroup>
#include <QtGui/QHeaderView>
#include <QtGui/QLabel>
#include <QtGui/QMainWindow>
#include <QtGui/QPushButton>
#include <QtGui/QWidget>
 
QT_BEGIN_NAMESPACE
 
class Ui_MainWindow
{
public:
    QWidget *centralWidget;
    QLabel *label_image;
    QPushButton *pushButton_display;
 
    void setupUi(QMainWindow *MainWindow)
    {
        if (MainWindow->objectName().isEmpty())
            MainWindow->setObjectName(QString::fromUtf8("MainWindow"));
        MainWindow->resize(770, 524);
        MainWindow->setStyleSheet(QString::fromUtf8("background-color: rgb(136, 162, 255);\n"
""));
        centralWidget = new QWidget(MainWindow);
        centralWidget->setObjectName(QString::fromUtf8("centralWidget"));
        label_image = new QLabel(centralWidget);
        label_image->setObjectName(QString::fromUtf8("label_image"));
        label_image->setGeometry(QRect(10, 10, 751, 461));
        label_image->setStyleSheet(QString::fromUtf8("background-color: rgba(62, 99, 255, 43);"));
        pushButton_display = new QPushButton(centralWidget);
        pushButton_display->setObjectName(QString::fromUtf8("pushButton_display"));
        pushButton_display->setGeometry(QRect(330, 480, 113, 32));
        MainWindow->setCentralWidget(centralWidget);
 
        retranslateUi(MainWindow);
 
        QMetaObject::connectSlotsByName(MainWindow);
    } // setupUi
 
    void retranslateUi(QMainWindow *MainWindow)
    {
        MainWindow->setWindowTitle(QApplication::translate("MainWindow", "MainWindow", 0, QApplication::UnicodeUTF8));
        label_image->setText(QString());
        pushButton_display->setText(QApplication::translate("MainWindow", "Push Me", 0, QApplication::UnicodeUTF8));
        Q_UNUSED(MainWindow);
    } // retranslateUi
 
};
 
namespace Ui {
    class MainWindow: public Ui_MainWindow {};
} // namespace Ui
 
QT_END_NAMESPACE
 
#endif // UI_MAINWINDOW_H

/********************************************************************************
** Form generated from reading ui file 'mainwindow.ui'
**
** Created: Mon Jun 15 22:04:49 2009
**      by: Qt User Interface Compiler version 4.5.1
**
** WARNING! All changes made in this file will be lost when recompiling ui file!
********************************************************************************/

#ifndef UI_MAINWINDOW_H
#define UI_MAINWINDOW_H

#include <QtCore/QVariant>
#include <QtGui/QAction>
#include <QtGui/QApplication>
#include <QtGui/QButtonGroup>
#include <QtGui/QHeaderView>
#include <QtGui/QLabel>
#include <QtGui/QMainWindow>
#include <QtGui/QPushButton>
#include <QtGui/QWidget>

QT_BEGIN_NAMESPACE

class Ui_MainWindow
{
public:
    QWidget *centralWidget;
    QLabel *label_image;
    QPushButton *pushButton_display;

    void setupUi(QMainWindow *MainWindow)
    {
        if (MainWindow->objectName().isEmpty())
            MainWindow->setObjectName(QString::fromUtf8("MainWindow"));
        MainWindow->resize(770, 524);
        MainWindow->setStyleSheet(QString::fromUtf8("background-color: rgb(136, 162, 255);\n"
""));
        centralWidget = new QWidget(MainWindow);
        centralWidget->setObjectName(QString::fromUtf8("centralWidget"));
        label_image = new QLabel(centralWidget);
        label_image->setObjectName(QString::fromUtf8("label_image"));
        label_image->setGeometry(QRect(10, 10, 751, 461));
        label_image->setStyleSheet(QString::fromUtf8("background-color: rgba(62, 99, 255, 43);"));
        pushButton_display = new QPushButton(centralWidget);
        pushButton_display->setObjectName(QString::fromUtf8("pushButton_display"));
        pushButton_display->setGeometry(QRect(330, 480, 113, 32));
        MainWindow->setCentralWidget(centralWidget);

        retranslateUi(MainWindow);

        QMetaObject::connectSlotsByName(MainWindow);
    } // setupUi

    void retranslateUi(QMainWindow *MainWindow)
    {
        MainWindow->setWindowTitle(QApplication::translate("MainWindow", "MainWindow", 0, QApplication::UnicodeUTF8));
        label_image->setText(QString());
        pushButton_display->setText(QApplication::translate("MainWindow", "Push Me", 0, QApplication::UnicodeUTF8));
        Q_UNUSED(MainWindow);
    } // retranslateUi

};

namespace Ui {
    class MainWindow: public Ui_MainWindow {};
} // namespace Ui

QT_END_NAMESPACE

#endif // UI_MAINWINDOW_H

To copy to clipboard, switch view to plain text mode 

[spirit]

try this

mainwindow.cpp

#include "mainwindow.h"
#include <QtGui> 
#include <QPixmap>
 
 
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(this)
{
    setupUi(this);
    connect( pushButton_display, SIGNAL( clicked() ), this, SLOT( display_pic() ) );
 
}
 
void MainWindow::display_pic()
{
    QPixmap pixmap("Dima.jpg");
 
    label_image->setPixmap(pixmap);
}

#include "mainwindow.h"
#include <QtGui> 
#include <QPixmap>


MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(this)
{
    setupUi(this);
    connect( pushButton_display, SIGNAL( clicked() ), this, SLOT( display_pic() ) );

}

void MainWindow::display_pic()
{
    QPixmap pixmap("Dima.jpg");

    label_image->setPixmap(pixmap);
}

To copy to clipboard, switch view to plain text mode 

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QMainWindow>
#include "ui_mainwindow.h"
 
 
class MainWindow : public QMainWindow, private Ui::MainWindowDLG
{
    Q_OBJECT
 
public:
  MainWindow(QWidget *parent = 0);
 
public slots:
 void display_pic();
 
};
 
#endif

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

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


class MainWindow : public QMainWindow, private Ui::MainWindowDLG
{
    Q_OBJECT

public:
  MainWindow(QWidget *parent = 0);

public slots:
 void display_pic();

};

#endif

To copy to clipboard, switch view to plain text mode 

[Lykurg]

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(this)

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(this)

To copy to clipboard, switch view to plain text mode 

Hi, a short side question. I pass everytime parent to the ctor of the base class. What's the advantage of passing this?

[spirit]

mistyped, of course must be passed parent.

[wysota]

Did you add the "mainwindow.ui" file to your project file and reran qmake? I guess you did... nevermind...

[Lykurg]

mistyped, of course must be passed parent.

Fine, than I can stop thinking about

[imagiro1]

Still not working.

[spirit]

ok, attach to your next post an archive with sources, pro-file and ui-file.

[wysota]

Are we blind or what?

The class is called Ui::MainWindow, not Ui::MainWindowDLG!

The line should say:

class MainWindow : public QMainWindow, private Ui::MainWindow

class MainWindow : public QMainWindow, private Ui::MainWindow

To copy to clipboard, switch view to plain text mode 

[spirit]

Are we blind or what?

The class is called Ui::MainWindow, not Ui::MainWindowDLG!

The line should say:

class MainWindow : public QMainWindow, private Ui::MainWindow

class MainWindow : public QMainWindow, private Ui::MainWindow

To copy to clipboard, switch view to plain text mode 

damn, you are right!

[imagiro1]

That's it! Builds without any problems. Of course when I try to run the program I get an error message and the program doesn't start. "The application image_2 quit unexpectedly" And I got to ignore, report, or relaunch. I guess the fun is just beginning. Thanks for your help. I got a feeling I'll be back.