private void InitData() { if (Files == null) { Files = new ObservableCollection <FileInfo>(); foreach (var f in FolderInfo.GetFiles()) { Files.Add(f); } } if (SubFolders == null) { try { SubFolders = new ObservableCollection <Folder>(); foreach (var d in FolderInfo.GetDirectories()) { Folder folder = new Folder(d.FullName); SubFolders.Add(folder); } } catch (Exception ex) { System.Diagnostics.Trace.WriteLine(ex.Message); } } }