Expected class-name before '{' token

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:

Code:

---

#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

---

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

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

Code:

---

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

---

Tried it, same result.

attach all sources.

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.

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

Sorry. Here we go...

main.cpp

Code:

---

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

---

mainwindow.cpp

Code:

---

#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);
}

---

mainwindow.h

Code:

---

#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

---

ui_mainwindow.h

Code:

---

/********************************************************************************
** 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

---

try this

mainwindow.cpp

Code:

---

#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);
}

---

mainwindow.h

Code:

---

#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

---

Quote:

---

Originally Posted by spirit

Code:

---

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

---

---

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

mistyped, of course must be passed parent.

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

Quote:

---

Originally Posted by spirit

mistyped, of course must be passed parent.

---

Fine, than I can stop thinking about :D

Still not working. :confused:

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

Are we blind or what?

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

The line should say:

Code:

---

class MainWindow : public QMainWindow, private Ui::MainWindow

---

Quote:

---

Originally Posted by wysota

Are we blind or what?

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

The line should say:

Code:

---

class MainWindow : public QMainWindow, private Ui::MainWindow

---

---

damn, you are right! :D

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.