C++ Qt实现动态增加垂直滚动条

#include "widget.h"
#include <QApplication>
#include <QtGui>
#include <QVBoxLayout>
#include <QTableWidget>
#include <QPushButton>
#include <QLabel>
#include <QScrollArea>
#include<QGroupBox>
#include<QCheckBox>
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QWidget *page = new QWidget; //整个内容
    QVBoxLayout* mainLayout = new QVBoxLayout(page);//铺满整个页面
    QScrollArea* scrollArea = new QScrollArea;
    QWidget* contentWidget = new QWidget;
    QVBoxLayout* contentLayout = new QVBoxLayout(contentWidget);//将layout绑定起来了
    scrollArea->setWidgetResizable(true);
    contentLayout->setAlignment(Qt::AlignTop);
    QTabWidget tabWidget;
    QWidget tab1,tab2;
    // 模拟数据
    QList<QString> caseNames;
       caseNames << "Case 1" << "Case 2" << "Case 3" << "Case 4" << "Case 5" << "Case 6" << "Case 7" << "Case 8";
       for (int i = 0; i < caseNames.size(); i++) {
           if (i % 2 == 0) { // 每两个groupBox为一行
               QHBoxLayout* rowLayout = new QHBoxLayout();
               contentLayout->addLayout(rowLayout);
           }
           QGroupBox* groupBox = new QGroupBox(caseNames[i], &tab1);
           groupBox->setFixedSize(200, 50);
           QVBoxLayout* groupBoxLayout = new QVBoxLayout(groupBox);
           groupBox->setLayout(groupBoxLayout);
           QCheckBox* checkBox = new QCheckBox(("Enabled"), groupBox);
           checkBox->setChecked(true);
           groupBoxLayout->addWidget(checkBox);
           QHBoxLayout* rowLayout = dynamic_cast<QHBoxLayout*>(contentLayout->itemAt(contentLayout->count() - 1)->layout());
           rowLayout->addWidget(groupBox);
       }
       scrollArea->setWidget(contentWidget); // 将内容窗口设置为滚动区域的子控件
       mainLayout->addWidget(&tabWidget);
       mainLayout->addWidget(scrollArea); // 将滚动区域添加到主布局中
    page->setLayout(mainLayout);
    page->show();
    return a.exec();
}