QGroupBox窗口部件提供了一个有标题的组合框。

组合框提供一个框架、一个标题和一个键盘快捷键，并且显示在它里面的其它不同窗口部件。

标题在上面，键盘快捷键移动键盘焦点到组合框的一个子窗口部件，并且子窗口部件将会排列在这个框架中地一个数组中。

官方example:

//mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QtGui>

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = 0);
    ~MainWindow();
private:
    QGroupBox *createFirstExclusiveGroup();
    QGroupBox *createSecondExclusiveGroup();
    QGroupBox *createNonExclusiveGroup();
    QGroupBox *createPushButtonGroup();
};

#endif // MAINWINDOW_H

#include "mainwindow.h"
#include <QtGui>
#include <QWidget>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    QGridLayout *grid = new QGridLayout;
    grid->addWidget(createFirstExclusiveGroup(),0,0);
    grid->addWidget(createSecondExclusiveGroup(),0,1);
    grid->addWidget(createNonExclusiveGroup(),1,0);
    grid->addWidget(createPushButtonGroup(),1,1);

    QWidget *widget = new QWidget;
    widget->setLayout(grid);
    widget->resize(480, 320);
    setCentralWidget(widget);

    setWindowTitle(tr("Group Boxes"));

}

MainWindow::~MainWindow()
{
}

QGroupBox *MainWindow::createFirstExclusiveGroup()
{
    QGroupBox *groupBox = new QGroupBox(tr("Exclusive Radio Buttons"));
    QRadioButton *radio1 = new QRadioButton(tr("&Radio button 1"));
    QRadioButton *radio2 = new QRadioButton(tr("R&adio button 2"));
    QRadioButton *radio3 = new QRadioButton(tr("Ra&dio button 3"));

    radio1->setChecked(true);

    QVBoxLayout *vbox = new QVBoxLayout;
    vbox->addWidget(radio1);
    vbox->addWidget(radio2);
    vbox->addWidget(radio3);
    vbox->addStretch(1);
    groupBox->setLayout(vbox);

    return groupBox;
}

QGroupBox *MainWindow::createSecondExclusiveGroup()
{
    QGroupBox *groupBox = new QGroupBox(tr("E&xclusive Radio Buttons"));
    groupBox->setCheckable(true);
    groupBox->setChecked(true);

    QRadioButton *radio1 = new QRadioButton(tr("Rad&io button1"));
    QRadioButton *radio2 = new QRadioButton(tr("Radi&o buttoon2"));
    QRadioButton *radio3 = new QRadioButton(tr("Radio &button3"));
    radio1->setChecked(true);
    QCheckBox *checkBox = new QCheckBox(tr("Ind&ependent checkbox"));
    checkBox->setChecked(true);

    QVBoxLayout *vbox = new QVBoxLayout;
    vbox->addWidget(radio1);
    vbox->addWidget(radio2);
    vbox->addWidget(radio3);
    vbox->addWidget(checkBox);
    groupBox->setLayout(vbox);

    return groupBox;
}

QGroupBox *MainWindow::createNonExclusiveGroup()
{
    QGroupBox *groupBox = new QGroupBox(tr("No-Exclusive Checkboxes"));
    groupBox->setFlat(true);

    QCheckBox *checkBox1 = new QCheckBox(tr("&Checkbox 1"));
    QCheckBox *checkBox2 = new QCheckBox(tr("C&heckbox 2"));
    checkBox2->setChecked(true);
    QCheckBox *tristateBox = new QCheckBox(tr("Tri-&state buttton"));
    tristateBox->setTristate(true);//是否启用三种状态切换
    tristateBox->setCheckState(Qt::PartiallyChecked);//介于Qt::Unchecked和Qt::Checked之间

    QVBoxLayout *vbox = new QVBoxLayout;
    vbox->addWidget(checkBox1);
    vbox->addWidget(checkBox2);
    vbox->addWidget(tristateBox);
    vbox->addStretch(1);
    groupBox->setLayout(vbox);
    return groupBox;
}

QGroupBox *MainWindow::createPushButtonGroup()
{
    QGroupBox *groupBox = new QGroupBox(tr("&Push Button"));
    groupBox->setCheckable(true);
    groupBox->setChecked(true);

    QPushButton *pushButton = new QPushButton(tr("&Normal Button"));
    QPushButton *toggleButton = new QPushButton(tr("&Toggle Button"));
    toggleButton->setCheckable(true);
    toggleButton->setChecked(true);

    QPushButton *flatButton = new QPushButton(tr("&Flat Button"));
    flatButton->setFlat(true);

    QPushButton *popupButton = new QPushButton(tr("Pop&up Button"));
    QMenu *menu = new QMenu(this);
    menu->addAction((tr("&First Item")));
    menu->addAction((tr("&Second Item")));
    menu->addAction((tr("Third Item")));
    menu->addAction(tr("F&ourth Item"));
    popupButton->setMenu(menu);

    QAction *newAction = menu->addAction(tr("Submenu"));
    QMenu *subMenu = new QMenu(tr("Popup Submenu"));
    subMenu->addAction(tr("Item 1"));
    subMenu->addAction(tr("Item 2"));
    subMenu->addAction(tr("Item 3"));
    newAction->setMenu(subMenu);

    QVBoxLayout *vbox = new QVBoxLayout;
    vbox->addWidget(pushButton);
    vbox->addWidget(toggleButton);
    vbox->addWidget(flatButton);
    vbox->addWidget(popupButton);
    groupBox->setLayout(vbox);
    return groupBox;
}