ViewDiskModel.DeleteSelectedFiles.Execute(null) не удаляет файлы

Мое приложение не удаляло файлы сохранения на странице загрузки в изолированном хранилище. Ниже приведены коды для удаления и класса ViewDiskModel.cs:

Загрузка страницы.cs

private void button2_Click(object sender, RoutedEventArgs e)
    {
        ViewDiskModel model = lstBox1.DataContext as ViewDiskModel;

        int m_iSelectedLoad = lstBox1.SelectedIndex;
        if (m_iSelectedLoad >= 0)
        {
            model.DeleteSelectedFiles.Execute(null);


        }

        MessageBox.Show("Files Successfully Deleted");
    } 

ViewDiskModel.cs:

 public class FileItem : ModelBase
    {

        public bool isChecked;
        public bool IsChecked
        {
            get { return this.isChecked; }
            set
            {
                this.isChecked = value;
                this.OnPropertyChanged("IsChecked");
            }
        }


        public string FileName { get; set; }
        public string FileText { get; set; }



    }

    public class ViewDiskModel : ModelBase
    {
        private IsolatedStorageFile currentStore;
        public IsolatedStorageFile Store
        {
            get
            {
                this.currentStore = this.currentStore ?? IsolatedStorageFile.GetUserStoreForApplication();
                return this.currentStore;
            }
        }

        private ObservableCollection<FileItem> _files;
        public ObservableCollection<FileItem> Files
        {
            get
            {
                this._files = this._files ?? this.LoadFiles();
                return this._files;
            }
        }

        private ObservableCollection<FileItem> LoadFiles()
        {
            ObservableCollection<FileItem> files = new ObservableCollection<FileItem>();

            foreach (string filePath in this.Store.GetFileNames())
                files.Add(new FileItem { FileName = filePath });
            return files;
        }

        private ICommand _deleteSelectedFiles;
        public ICommand DeleteSelectedFiles
        {
            get
            {
                this._deleteSelectedFiles = this._deleteSelectedFiles ?? new DelegateCommand(this.OnDeleteSelected);
                return this._deleteSelectedFiles;
            }
        }

        private ICommand _readSelectedFiles;
        public ICommand ReadSelectedFiles
        {
            get
            {
                this._readSelectedFiles = this._readSelectedFiles ?? new DelegateCommand(this.OnReadSelected);
                return this._readSelectedFiles;
            }
        }

        private void OnDeleteSelected()
        {
            IsolatedStorageFile storage = IsolatedStorageFile.GetUserStoreForApplication();
            List<FileItem> removedItems = new List<FileItem>();
            foreach (var item in this.Files)
            {
                if (item.IsChecked)
                    if (storage.FileExists(item.FileName))
                    {
                        storage.DeleteFile(item.FileName);
                        removedItems.Add(item);
                    }
            }

            foreach (var item in removedItems)
                this.Files.Remove(item);
        }

        private void OnReadSelected()
        {
            IsolatedStorageFile storage = IsolatedStorageFile.GetUserStoreForApplication();
            List<FileItem> removedItems = new List<FileItem>();
            foreach (var item in this.Files)
            {
                if (item.IsChecked)
                    if (storage.FileExists(item.FileName))
                    {
                        storage.DeleteFile(item.FileName);
                        removedItems.Add(item);
                    }
            }

            foreach (var item in removedItems)
                this.Files.Remove(item);
        }


    }

Загрузка страницы. XAML:

<!--ContentPanel - place additional content here-->
        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0" DataContext="{StaticResource vmDiskModel}">
            <Button Content="Back" Height="72" HorizontalAlignment="Left" Margin="0,530,0,0" Name="button1" VerticalAlignment="Top" Width="160" Click="button1_Click" />
            <Button Content="Delete" Height="72" HorizontalAlignment="Left" Margin="150,530,0,0" Name="button2" VerticalAlignment="Top" Width="160" Click="button2_Click" />
            <Button Content="Continue" Height="72" HorizontalAlignment="Left" Margin="296,530,0,0" Name="button3" VerticalAlignment="Top" Width="160" Click="button3_Click" />
            <TextBlock Height="30" HorizontalAlignment="Left" Margin="6,6,0,0" Name="textBlock1" Text="PLease select a save file to load." VerticalAlignment="Top" />
            <ListBox ItemsSource="{Binding Files}" Margin="0,42,0,115" SelectionChanged="ListBox_SelectionChanged" Name="lstBox1" DataContext="{StaticResource vmDiskModel}">
                <ListBox.ItemTemplate>
                    <DataTemplate >
                        <CheckBox IsChecked="{Binding IsChecked}" Content="{Binding FileName}" />
                    </DataTemplate>
                </ListBox.ItemTemplate>
            </ListBox>
        </Grid>
    </Grid>