error in this below code any one solve plz

can't convert type base DevExpress.XtraEditorslist box controls.selected items collections to system.IO.Directoryinfo

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using DevExpress.XtraEditors;

namespace browserlist
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            
            foreach (DriveInfo d1 in DriveInfo.GetDrives())
                drivelist.Items.Add(d1);
        }

        private void drivelist_SelectedIndexChanged(object sender, EventArgs e)
        {
            folderlist.Items.Clear();
            try
            {
                DriveInfo drive = (DriveInfo)drivelist.SelectedItem;
                foreach (DirectoryInfo driveinfo in drive.RootDirectory.GetDirectories())
                    folderlist.Items.Add(driveinfo);

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void folderlist_SelectedIndexChanged(object sender, EventArgs e)
        {
            fileslist.Items.Clear();
            DirectoryInfo dir = (DirectoryInfo)folderlist.SelectedItems;
            foreach (FileInfo f1 in dir.GetFiles())
                fileslist.Items.Add(f1);
        }
    }
}