MDI [Windows XP]

[wysota]

This is a bug in your code and not in QMenu. Focus on correcting your own code instead of chasing non existing bugs in Qt. Try to compose a minimal compilable example reproducing your problem or use a debugger to find out where exactly it crashes. The code you posted doesn't make much sense, by the way. You're starting a modal dialog which at the same time you'd like to be part of MDI. The two don't go together.

[wirasto]

But, why in Linux is fine?

And, I think, I can opened more dialog if use QAction on QToolbar.

[axeljaeger]

Just because it works on one OS does not mean you did it right. You should rather try your application on as many operating systems as possible to find bugs that might also affect the other plattforms but not (yet) show up.

I dont think that it makes any difference how to open a dialog, e.g. a QPushButton, a QAction or a QMenu.

[wirasto]

Really ? well, this is my sample code

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QMainWindow>
#include <QToolBar>
#include <QWorkspace>
#include <QAction>
#include <QMenuBar>
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow(QWidget *parent = 0);
 
private:
 
    QToolBar *toolbar;
    QAction *toolbar0, *toolbar1;
 
    QWorkspace * ws;
 
    QMenuBar *mainmenu;
    QMenu *mn;
 
private slots:
    void bukakelas();
    void bukaanggota();
 
};
 
#endif // MAINWINDOW_H

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QToolBar>
#include <QWorkspace>
#include <QAction>
#include <QMenuBar>

class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow(QWidget *parent = 0);

private:

    QToolBar *toolbar;
    QAction *toolbar0, *toolbar1;

    QWorkspace * ws;

    QMenuBar *mainmenu;
    QMenu *mn;

private slots:
    void bukakelas();
    void bukaanggota();

};

#endif // MAINWINDOW_H

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mainwindow.cpp

#include "mainwindow.h"
#include <QDialog>
 
class FrmKelas: public QDialog
{
public:
    FrmKelas(QWidget *parent=0):QDialog(parent) { setFixedSize(200, 300); }
 
};
 
 
class FrmAnggota: public QDialog
{
public:
    FrmAnggota(QWidget *parent=0):QDialog(parent) { setFixedSize(400, 100); }
 
};
 
 
MainWindow::MainWindow(QWidget *parent)
        :QMainWindow(parent)
{
 
    toolbar=addToolBar("Tahede");
    toolbar0=new QAction(QIcon(":/icon/0.png"), tr("Kelas"), this);
    connect( toolbar0, SIGNAL(triggered()), this, SLOT(bukakelas()) );
    toolbar1=new QAction(QIcon(":/icon/1.png"), tr("Anggota"), this);
    connect( toolbar1, SIGNAL(triggered()), this, SLOT(bukaanggota()) );
    toolbar->addAction(toolbar0);
    toolbar->addAction(toolbar1);
 
    ws=new QWorkspace(this);
    setCentralWidget(ws);
 
    mainmenu=new QMenuBar(this);
    setMenuBar(mainmenu);
 
 
    mn=new QMenu("Master");
    //mn->addAction("Kelas", this, SLOT(bukakelas()));
    //mn->addAction("Anggota", this, SLOT(bukaanggota()));
    mn->addAction(toolbar0);
    mn->addAction(toolbar1);
    mainmenu->addMenu(mn);
}
 
 
void MainWindow::bukakelas()
{
    FrmKelas form(this);
    ws->addWindow(&form);
    form.exec();
}
 
void MainWindow::bukaanggota()
{
    FrmAnggota form(this);
    ws->addWindow(&form);
    form.exec();
}

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

class FrmKelas: public QDialog
{
public:
    FrmKelas(QWidget *parent=0):QDialog(parent) { setFixedSize(200, 300); }

};


class FrmAnggota: public QDialog
{
public:
    FrmAnggota(QWidget *parent=0):QDialog(parent) { setFixedSize(400, 100); }

};


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

    toolbar=addToolBar("Tahede");
    toolbar0=new QAction(QIcon(":/icon/0.png"), tr("Kelas"), this);
    connect( toolbar0, SIGNAL(triggered()), this, SLOT(bukakelas()) );
    toolbar1=new QAction(QIcon(":/icon/1.png"), tr("Anggota"), this);
    connect( toolbar1, SIGNAL(triggered()), this, SLOT(bukaanggota()) );
    toolbar->addAction(toolbar0);
    toolbar->addAction(toolbar1);

    ws=new QWorkspace(this);
    setCentralWidget(ws);

    mainmenu=new QMenuBar(this);
    setMenuBar(mainmenu);


    mn=new QMenu("Master");
    //mn->addAction("Kelas", this, SLOT(bukakelas()));
    //mn->addAction("Anggota", this, SLOT(bukaanggota()));
    mn->addAction(toolbar0);
    mn->addAction(toolbar1);
    mainmenu->addMenu(mn);
}


void MainWindow::bukakelas()
{
    FrmKelas form(this);
    ws->addWindow(&form);
    form.exec();
}

void MainWindow::bukaanggota()
{
    FrmAnggota form(this);
    ws->addWindow(&form);
    form.exec();
}

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main.cpp

#include <QtGui/QApplication>
#include "mainwindow.h"
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

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

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

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Where I make a mistake?

[axeljaeger]

When you call exec on a dialog, it will block the application as long as the dialog stays open. Use show instead and create the dialog on the heap instead of the stack.