创建2级窗口问题 [复制链接]

在一级窗口的操函数中做以下代码

  QDialog *dialog = new QDialog(this);
  QPushButton *pushButton = new QPushButton;
  QComboBox *comboBox = new QComboBox;
  push -> setText(tr("exit"));

  QHBoxLayout *pDlgLayout = new QHBoxLayout(dialog);
  pDlgLayout -> addWidget(pushButton);
  pDlgLayout -> addWidget(comboBox);


  QDialog c;
  c.exec();

生成的是白板，按键和下拉窗没添加进去，求解

  QHBoxLayout *pDlgLayout = new QHBoxLayout;
  pDlgLayout -> addWidget(pushButton);
  pDlgLayout -> addWidget(comboBox);
dialog->setLayout(pDlgLayout);