Hi. I have same question with a little difference. I build a form with tab widget. After running, i make it unvisible, and call with another button click. On close the child form is deleting with own objects. My problem is, with tab widget. Because i call it with reference, so on child form close its deleting from heap. After that if i click the button second time, its crashing. I cant copy my existed tab widget, or cant create a copy. How can i do it ?

Here is my dirty code

Qt Code: 
  1. void MainWindow::on_action_Config_triggered()
  2. {    
  3.     confw = new QDialog(this);
  4.     confw->setModal(true);
  5.     confw->setSizeGripEnabled(false);
  6.  
  7.     confw->setObjectName("confwid");
  8.     confw->setWindowTitle("Configuration");
  9.  
  10.     QWidget *tab = new QWidget;
  11.     tab = (QWidget *)ui->tab1;  //existing tab widget object, which i created with qt creator for another mainwindow object
  12.     tab->setParent(confw);      // on confw delete, its deleting too. because i cant make it copy!!! :(
  13.  
  14.     tab->show();
  15.     confw->setMaximumSize((tab->width()+10),(tab->height()+10));
  16.     confw->setMinimumSize((tab->width()+10),(tab->height()+10));
  17.     ui->pushButton->setVisible(false);
  18.     confw->resize(tab->size().width()+10,tab->size().height()+10);
  19.     confw->setGeometry(QStyle::alignedRect(Qt::LeftToRight, Qt::AlignCenter,confw->size(),
  20.                                                       qApp->desktop()->availableGeometry()));
  21.  
  22.     QPushButton *pushbutton = new QPushButton(ui->groupBox_6);
  23.     pushbutton->setText("Save");    
  24.     pushbutton->setGeometry(ui->pushButton->geometry());
  25.     pushbutton->setIcon(ui->pushButton->icon());
  26.     connect(pushbutton,SIGNAL(clicked()),this,SLOT(configcontrol()));
  27.     connect(pushbutton,SIGNAL(clicked()),confw,SLOT(close()));
  28.     ui->groupBox_6->setVisible(true);
  29.     ui->groupBox_6->setEnabled(true);
  30.     pushbutton->setVisible(true);
  31.     pushbutton->setEnabled(true);
  32.     pushbutton->show();
  33.     confw->showNormal();
  34. }
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Regards.