Hi everyone, I have just downloaded QT 5.4.1 for a couple of days. Because there is no book for Qt 5, I use the book named "C++ GUI Programming with Qt 4". I'm learning about QDialog and Qt Designer, and I copied the source code from that book to run on my Qt. However, it didn't work but announced "The inferior stopped because it triggered an exception.". I don't know why. Here are he source code:
The header:
Qt Code: 
  1. #ifndef GOTOCELLDIALOG_H
  2. #define GOTOCELLDIALOG_H
  3.  
  4. #include <QDialog>
  5. #include "ui_gotocelldialog.h"
  6.  
  7. namespace Ui
  8. {
  9. class GoToCellDialog;
  10. }
  11.  
  12. class GoToCellDialog : public QDialog, public Ui::GoToCellDialog
  13. {
  14.     Q_OBJECT
  15. public:
  16.     explicit GoToCellDialog(QWidget *parent = 0);
  17.     ~GoToCellDialog();
  18. private slots:
  19.     void on_lineEdit_textChanged();
  20. private:
  21.     Ui::GoToCellDialog *ui;
  22. };
  23.  
  24. #endif // GOTOCELLDIALOG_H
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The implementation of the class:
Qt Code: 
  1. #include "gotocelldialog.h"
  2.  
  3. GoToCellDialog::GoToCellDialog(QWidget *parent)
  4.     :QDialog(parent),
  5.     ui(new Ui::GoToCellDialog)
  6. {
  7.     ui->setupUi(this);
  8.  
  9.     QRegExp regExp("[A-Za-z][1-9][0-9]{0,2}");
  10.     lineEdit->setValidator(new QRegExpValidator(regExp, this));
  11.  
  12.     connect(cancelButton, SIGNAL(clicked()), this, SLOT(reject()));
  13.     connect(okButton, SIGNAL(clicked()), this, SLOT(accept()));
  14. }
  15.  
  16. GoToCellDialog::~GoToCellDialog()
  17. {
  18.     delete ui;
  19. }
  20.  
  21. void GoToCellDialog::on_lineEdit_textChanged()
  22. {
  23.     okButton->setEnabled(lineEdit->hasAcceptableInput());
  24. }
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The main source code:
Qt Code: 
  1. #include "gotocelldialog.h"
  2. #include <QApplication>
  3.  
  4. int main(int argc, char *argv[])
  5. {
  6.     QApplication a(argc, argv);
  7.     GoToCellDialog w;
  8.     w.show();
  9.  
  10.     return a.exec();
  11. }
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There's also a .ui file that contains a label, lineEdit, okButton and cancelButton. Please help me solve this error. Thanks in advance.