QFileSystemModel

#include "dialog.h"
#include "ui_dialog.h"

Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);
    QString sPath = "E:/";
    dirmodel = new QFileSystemModel(this);
    dirmodel->setFilter(QDir::NoDotAndDotDot |QDir::AllDirs);
    dirmodel->setRootPath(sPath);

    ui->treeView->setModel(dirmodel);
    filemodel = new QFileSystemModel(this);
    filemodel->setFilter(QDir::NoDotAndDotDot |QDir::Files);
    filemodel->setRootPath(sPath);
    ui->listView->setModel(filemodel);
}

Dialog::~Dialog()
{
    delete ui;
}

void Dialog::on_treeView_clicked(const QModelIndex &index)
{
    QString sPath = dirmodel->fileInfo(index).absoluteFilePath();
    ui->listView->setRootIndex(filemodel->setRootPath(sPath));
}