It has been a while since I tried programming using QT so I might be doing something very newbish.

Here is the situation:
--Ubuntu 8.10
--QT 4.5 binary install that includes Qt Creator 1.0

Application:
--MainWindow with two dialog boxes

I autogenerate the dialog code using Qt Creator so I have two classes that are called Ui_Dialog and Ui_Dialog2.

When I try to initialize them in the MainWindow constructor the entire application seg faults when it is run.

Here is the code:

Qt Code: 
  1. #ifndef MAINWINDOW_H
  2. #define MAINWINDOW_H
  3.  
  4. #include <QtGui/QMainWindow>
  5. #include <QDialog>
  6.  
  7. namespace Ui
  8. {
  9.     class Dialog;
  10.     class Dialog2;
  11.     class MainWindowClass;
  12. }
  13.  
  14. class MainWindow : public QMainWindow
  15. {
  16.     Q_OBJECT
  17.  
  18. public:
  19.     MainWindow(QWidget *parent = 0);
  20.     ~MainWindow();
  21.  
  22. private:
  23.     QDialog dOne;
  24.     QDialog dTwo;
  25.  
  26.     Ui::MainWindowClass *ui;
  27.     Ui::Dialog  *p_dOne;
  28.     Ui::Dialog2 *p_dTwo;
  29. };
  30.  
  31. #endif // MAINWINDOW_H
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Qt Code: 
  1. #include "mainwindow.h"
  2. #include "ui_dialog.h"
  3. #include "ui_dialog2.h"
  4. #include "ui_mainwindow.h"
  5.  
  6. MainWindow::MainWindow(QWidget *parent)
  7.     : QMainWindow(parent), ui(new Ui::MainWindowClass)
  8. {
  9.   ui->setupUi(this);
  10.   p_dOne->setupUi(&dOne);
  11.   p_dTwo->setupUi(&dTwo);
  12. }
  13.  
  14. MainWindow::~MainWindow()
  15. {
  16.     delete ui;
  17. }
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Qt Code: 
  1. /********************************************************************************
  2. ** Form generated from reading ui file 'dialog.ui'
  3. **
  4. ** Created: Sat Mar 21 22:13:51 2009
  5. **      by: Qt User Interface Compiler version 4.5.0
  6. **
  7. ** WARNING! All changes made in this file will be lost when recompiling ui file!
  8. ********************************************************************************/
  9.  
  10. #ifndef UI_DIALOG_H
  11. #define UI_DIALOG_H
  12.  
  13. #include <QtCore/QVariant>
  14. #include <QtGui/QAction>
  15. #include <QtGui/QApplication>
  16. #include <QtGui/QButtonGroup>
  17. #include <QtGui/QDialog>
  18. #include <QtGui/QDialogButtonBox>
  19. #include <QtGui/QGridLayout>
  20. #include <QtGui/QHeaderView>
  21. #include <QtGui/QLabel>
  22.  
  23. QT_BEGIN_NAMESPACE
  24.  
  25. class Ui_Dialog
  26. {
  27. public:
  28.     QGridLayout *gridLayout;
  29.     QLabel *label;
  30.     QDialogButtonBox *buttonBox;
  31.  
  32.     void setupUi(QDialog *Dialog)
  33.     {
  34.         if (Dialog->objectName().isEmpty())
  35.             Dialog->setObjectName(QString::fromUtf8("Dialog"));
  36.         Dialog->resize(400, 100);
  37.         gridLayout = new QGridLayout(Dialog);
  38.         gridLayout->setObjectName(QString::fromUtf8("gridLayout"));
  39.         label = new QLabel(Dialog);
  40.         label->setObjectName(QString::fromUtf8("label"));
  41.  
  42.         gridLayout->addWidget(label, 0, 0, 1, 1);
  43.  
  44.         buttonBox = new QDialogButtonBox(Dialog);
  45.         buttonBox->setObjectName(QString::fromUtf8("buttonBox"));
  46.         buttonBox->setOrientation(Qt::Horizontal);
  47.         buttonBox->setStandardButtons(QDialogButtonBox::Cancel|QDialogButtonBox::Ok);
  48.  
  49.         gridLayout->addWidget(buttonBox, 1, 0, 1, 1);
  50.  
  51.  
  52.         retranslateUi(Dialog);
  53.         QObject::connect(buttonBox, SIGNAL(accepted()), Dialog, SLOT(accept()));
  54.         QObject::connect(buttonBox, SIGNAL(rejected()), Dialog, SLOT(reject()));
  55.  
  56.         QMetaObject::connectSlotsByName(Dialog);
  57.     } // setupUi
  58.  
  59.     void retranslateUi(QDialog *Dialog)
  60.     {
  61.         Dialog->setWindowTitle(QApplication::translate("Dialog", "Dialog", 0, QApplication::UnicodeUTF8));
  62.         label->setText(QApplication::translate("Dialog", "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0//EN\" \"http://www.w3.org/TR/REC-html40/strict.dtd\">\n"
  63. "<html><head><meta name=\"qrichtext\" content=\"1\" /><style type=\"text/css\">\n"
  64. "p, li { white-space: pre-wrap; }\n"
  65. "</style></head><body style=\" font-family:'Sans Serif'; font-size:9pt; font-weight:400; font-style:normal;\">\n"
  66. "<p align=\"center\" style=\" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;\">Dialog One</p></body></html>", 0, QApplication::UnicodeUTF8));
  67.         Q_UNUSED(Dialog);
  68.     } // retranslateUi
  69.  
  70. };
  71.  
  72. namespace Ui {
  73.     class Dialog: public Ui_Dialog {};
  74. } // namespace Ui
  75.  
  76. QT_END_NAMESPACE
  77.  
  78. #endif // UI_DIALOG_H
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Qt Code: 
  1. /********************************************************************************
  2. ** Form generated from reading ui file 'dialog2.ui'
  3. **
  4. ** Created: Sat Mar 21 22:15:00 2009
  5. **      by: Qt User Interface Compiler version 4.5.0
  6. **
  7. ** WARNING! All changes made in this file will be lost when recompiling ui file!
  8. ********************************************************************************/
  9.  
  10. #ifndef UI_DIALOG2_H
  11. #define UI_DIALOG2_H
  12.  
  13. #include <QtCore/QVariant>
  14. #include <QtGui/QAction>
  15. #include <QtGui/QApplication>
  16. #include <QtGui/QButtonGroup>
  17. #include <QtGui/QDialog>
  18. #include <QtGui/QDialogButtonBox>
  19. #include <QtGui/QGridLayout>
  20. #include <QtGui/QHeaderView>
  21. #include <QtGui/QLabel>
  22.  
  23. QT_BEGIN_NAMESPACE
  24.  
  25. class Ui_Dialog2
  26. {
  27. public:
  28.     QGridLayout *gridLayout;
  29.     QLabel *label;
  30.     QDialogButtonBox *buttonBox;
  31.  
  32.     void setupUi(QDialog *Dialog2)
  33.     {
  34.         if (Dialog2->objectName().isEmpty())
  35.             Dialog2->setObjectName(QString::fromUtf8("Dialog2"));
  36.         Dialog2->resize(400, 100);
  37.         gridLayout = new QGridLayout(Dialog2);
  38.         gridLayout->setObjectName(QString::fromUtf8("gridLayout"));
  39.         label = new QLabel(Dialog2);
  40.         label->setObjectName(QString::fromUtf8("label"));
  41.  
  42.         gridLayout->addWidget(label, 0, 0, 1, 1);
  43.  
  44.         buttonBox = new QDialogButtonBox(Dialog2);
  45.         buttonBox->setObjectName(QString::fromUtf8("buttonBox"));
  46.         buttonBox->setOrientation(Qt::Horizontal);
  47.         buttonBox->setStandardButtons(QDialogButtonBox::Cancel|QDialogButtonBox::Ok);
  48.  
  49.         gridLayout->addWidget(buttonBox, 1, 0, 1, 1);
  50.  
  51.  
  52.         retranslateUi(Dialog2);
  53.         QObject::connect(buttonBox, SIGNAL(accepted()), Dialog2, SLOT(accept()));
  54.         QObject::connect(buttonBox, SIGNAL(rejected()), Dialog2, SLOT(reject()));
  55.  
  56.         QMetaObject::connectSlotsByName(Dialog2);
  57.     } // setupUi
  58.  
  59.     void retranslateUi(QDialog *Dialog2)
  60.     {
  61.         Dialog2->setWindowTitle(QApplication::translate("Dialog2", "Dialog", 0, QApplication::UnicodeUTF8));
  62.         label->setText(QApplication::translate("Dialog2", "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0//EN\" \"http://www.w3.org/TR/REC-html40/strict.dtd\">\n"
  63. "<html><head><meta name=\"qrichtext\" content=\"1\" /><style type=\"text/css\">\n"
  64. "p, li { white-space: pre-wrap; }\n"
  65. "</style></head><body style=\" font-family:'Sans Serif'; font-size:9pt; font-weight:400; font-style:normal;\">\n"
  66. "<p align=\"center\" style=\" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px;\">Dialog Two</p></body></html>", 0, QApplication::UnicodeUTF8));
  67.         Q_UNUSED(Dialog2);
  68.     } // retranslateUi
  69.  
  70. };
  71.  
  72. namespace Ui {
  73.     class Dialog2: public Ui_Dialog2 {};
  74. } // namespace Ui
  75.  
  76. QT_END_NAMESPACE
  77.  
  78. #endif // UI_DIALOG2_H
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The last two are automatically generated. I cannot figure out why initializing them both in the MainWindow constructor would cause a seg fault!!!