/// <summary>
        /// Event handler for the Load button click event.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private async void LoadButton_Clicked(object sender, RoutedEventArgs e)
        {
            // Loads a previously saved drawing.
            FileOpenPicker picker = new FileOpenPicker();

            picker.FileTypeFilter.Add(DefaultFileExtension);
            picker.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;

            var file = await picker.PickSingleFileAsync();

            if (file != null)
            {
                using (var stream = await file.OpenAsync(FileAccessMode.Read))
                {
                    try
                    {
                        await DrawingPanel.LoadStrokesFromStreamAsync(stream);

                        DrawingPanel.Update();
                    }
                    catch (Exception)
                    {
                        rootPage.NotifyUser("Unable to load file.", NotifyType.ErrorMessage);
                    }
                }
            }
        }