private void PageLoadedHandler(object sender, RoutedEventArgs e)
        {
            CheckDisposedState();

            if (_folderTree.Items.Count == 0)
            {
                _folderTree.Items.Clear();
                _findingPhotosStage.SelectedFolders.Clear();
                _findingPhotosStage.DeselectedFolders.Clear();

                // Fill folder treeView
                for (int i = 0; i < _findingPhotosStage.SearchPaths.Length; i++)
                {
                    AddFolder(new DirectoryInfo(_findingPhotosStage.SearchPaths[i]), _folderTree, 0);
                }

                // No files found
                if (_folderTree.Items.Count == 0)
                {
                    MessageDialog.Show((string)FindResource(Constants.MessageNoFilesFoundKey));
                    if (ExecutionEngine.Config.IsBluetoothEnabled())
                    {
                        _findingPhotosStage.SwitchToSelectDeviceScreen();
                    }
                    else
                    {
                        _findingPhotosStage.SwitchToWelcomeScreen();
                    }
                    return;
                }

                // Check all folders
                foreach (FolderItemControl folder in _folderTree.Items)
                {
                    folder.IsExpanded = true;
                }

                _foldersCount.Text = _findingPhotosStage.SelectedFolders.Count.ToString();

                SetAltIndexes();
            }
            _nextButton.IsEnabled = _findingPhotosStage.SelectedFolders.Count > 0;
        }
 private void ButtonPrevStageClickHandler(object sender, RoutedEventArgs e)
 {
     CheckDisposedState();
     _findingPhotosStage.SwitchToSelectDeviceScreen();
 }