This is my first show dialog
void ProjectModel::wellManager()

{     DialogWellManager dlg(this, DialogWellManager::editor);     dlg.exec(); }

in DialogWellManager, I called another Qdialog,the program crashed.
void DialogWellManager::on_tbAddWell_clicked()
{
    DialogAddWell dlg(_model,nullptr);
    if (dlg.exec() == QDialog::Accepted)

{         updateToWell();         refreshTable();     }

}