How to use QList class to construct  list to contain  other components.
The following code is based on Qt4.0 SimpleWizard Example,I just make a little modification to let me understand easily.
//test.h code
#include <QDialog>
#include <QList>
class QLabel;
class QPushButton;
class QString;
class QVBoxLayout;
class QHBoxLayout;
class Test:public QDialog
{
Q_OBJECT
public:
    Test();
    void updateLabel(int index);
private slots:
    void nextBtnClicked();
    void backBtnClicked();
private:
    QList<QString>  contents;
    QLabel *label;
    QPushButton *nextBtn;
    QPushButton *backBtn;
    QHBoxLayout *btnLayout;
    QVBoxLayout *mainLayout;
    int curIndex;
};
//test.cpp code
#include "test.h"
#include <QList>
#include <QPushButton>
#include <QLabel>
#include <QString>
#include <QVBoxLayout>
#include <QHBoxLayout>
Test::Test()
{
backBtn=new QPushButton(tr("Back"));
nextBtn=new QPushButton(tr("Next"));
connect(backBtn,SIGNAL(clicked()),this,SLOT(backBtnClicked()));
connect(nextBtn,SIGNAL(clicked()),this,SLOT(nextBtnClicked()));
btnLayout=new QHBoxLayout;
btnLayout->addStretch(1);
btnLayout->addWidget(backBtn);
btnLayout->addWidget(nextBtn);
label=new QLabel("");
mainLayout=new QVBoxLayout;
mainLayout->addWidget(label);
mainLayout->addLayout(btnLayout);
for(int i=0;i<10;++i)
contents.append(QString::number(i));
curIndex=0;
updateLabel(curIndex);
setLayout(mainLayout);
}
void Test::updateLabel(int index)
{
QLabel *newLabel=new QLabel(QString::number(index));
mainLayout->addWidget(newLabel);
setWindowTitle(tr("%1 of %2").arg(index).arg(contents.size()));
if(index==contents.size())
{
nextBtn->setEnabled(false);
backBtn->setEnabled(true);
}
else if(index==0)
{
nextBtn->setEnabled(true);
backBtn->setEnabled(false);
}
else
{
nextBtn->setEnabled(true);
backBtn->setEnabled(true);
}
}
void Test::backBtnClicked()
{
if(curIndex>0)
{
curIndex--;
updateLabel(curIndex);
}
}
void Test::nextBtnClicked()
{
if(curIndex<contents.size())
{
curIndex++;
updateLabel(curIndex);
}
}

The above code is very easy,but it also has a bug that  I don't know how to control the button's status(enabled or disabled)