QStackeddialog.h

#ifndef QSTACKEDDIALOG_H
#define QSTACKEDDIALOG_H

#include <QDialog>
#include <QListWidget>
#include <QStackedWidget>
#include <QLabel>

class QStackeddialog : public QDialog
{
    Q_OBJECT

public:
    QStackeddialog(QWidget *parent = nullptr);
    ~QStackeddialog();
private:
    QListWidget *list;
    QStackedWidget *stack;
    QLabel *label1;
    QLabel *label2;
    QLabel *label3;
};
#endif // QSTACKEDDIALOG_H

QStackeddialog.cpp

#include "qstackeddialog.h"
#include <QHBoxLayout>

QStackeddialog::QStackeddialog(QWidget *parent)
    : QDialog(parent)
{
    setWindowTitle(tr("StackedWidget"));
    list = new QListWidget(this);//创建一个QListwidget控件对象
    //在新建的QListwidget 控件中插入三个条目，作为选择
    list->insertItem(0,tr("windows1"));
    list->insertItem(1,tr("windows2"));
    list->insertItem(2,tr("windows3"));
    //创建三个QLabel 标签控件对象，作为堆栈窗口需要显示的三层窗体
    label1 = new QLabel(tr("windwosTest1"));
    label2 = new QLabel(tr("windowsText2"));
    label3 = new QLabel(tr("wondowsText3"));
    //新建一个QStackedWidget堆栈窗体对象
    stack = new QStackedWidget(this);
    //将创建的三个label对象依次插入堆栈窗体中
    stack->addWidget(label1);
    stack->addWidget(label2);
    stack->addWidget(label3);
    //创建一个布局控件
    QHBoxLayout *MainLayout = new QHBoxLayout(this);
    MainLayout->setMargin(5);//设定离边框的边距为5
    MainLayout->setSpacing(5);//各个控件之间的间距为5
    MainLayout->addWidget(list);
    MainLayout->addWidget(stack,0,Qt::AlignHCenter);
    MainLayout->setStretchFactor(list,1);
    MainLayout->setStretchFactor(stack,1);
    connect(list,SIGNAL(currentRowChanged(int)),stack,SLOT(setCurrentIndex(int)));

}

QStackeddialog::~QStackeddialog() {}

main.cpp

#include "qstackeddialog.h"

#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QStackeddialog w;
    w.show();
    return a.exec();
}

运行图