private void OpenFilePickerDialog(MainViewModelService _service)
        {
            OpenFileDialog dialog = new OpenFileDialog();
            bool?          result = dialog.ShowDialog();

            if (result.HasValue && result.Value)
            {
                _service.PickedFileName = dialog.FileName;
                if (_service.FilePicked != null)
                {
                    _service.FilePicked.Invoke();
                }
            }
        }
 public MainViewModel()
 {
     this.GetFile        = new RelayCommand(() => Messenger.Default.Send(_service));
     _service            = new MainViewModelService();
     _service.FilePicked = this.FilePicked;
 }