WPF simple file resource management

<Window X: class = "wpffolderexplorer. mainwindow "xmlns =" http://schemas.microsoft.com/winfx/2006/xaml/presentation "xmlns: x =" http://schemas.microsoft.com/winfx/2006/xaml "xmlns: My =" CLR-namespace: wpffolderexplorer "Title =" folder Explorer "Height =" 350 "width =" 525 "> <window. resources> <! -- Objectdataprovider: wraps and creates an object that can be used as the binding source. --> <Objectdataprovider X: Key = "rootfolderdataprovider"> <! -- Objectinstance: object instance --> <objectdataprovider. objectinstance> <! -- Fullpath: an attribute of the folder class --> <my: folder fullpath = "C: \ Program Files \"/> </objectdataprovider. objectinstance> </objectdataprovider> <! -- Hierarchicaldatatemplate: hierarchical data template --> 
using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.IO;using System.Collections.ObjectModel;namespace WPFFolderExplorer{    public class Folder    {        private DirectoryInfo _folder;        private ObservableCollection<Folder> _subFolders;        private ObservableCollection<FileInfo> _files;        public Folder()        {            this.FullPath = @"c:\Program Files\";        }        public string Name        {            get            {                return this._folder.Name;            }        }        public string FullPath        {            get            {                return this._folder.FullName;            }            set            {                if (Directory.Exists(value))                {                    this._folder = new DirectoryInfo(value);                }                else                {                    throw new ArgumentException("must exist", "fullPath");                }            }        }        public ObservableCollection<FileInfo> Files        {            get            {                if (this._files == null)                {                    this._files = new ObservableCollection<FileInfo>();                    FileInfo[] fi = this._folder.GetFiles();                    for (int i = 0; i < fi.Length; i++)                    {                        this._files.Add(fi[i]);                    }                }                return this._files;            }        }        public ObservableCollection<Folder> SubFolders        {            get            {                if (this._subFolders == null)                {                    this._subFolders = new ObservableCollection<Folder>();                    DirectoryInfo[] di = this._folder.GetDirectories();                    for (int i = 0; i < di.Length; i++)                    {                        Folder newFolder = new Folder();                        newFolder.FullPath = di[i].FullName;                        this._subFolders.Add(newFolder);                    }                }                return this._subFolders;            }        }    }}