public ValueConverterViewModel()
        {
            _numberConverterFactory = new NumberConverterFactory();

            ConverterNames = new ObservableCollection <string>(_numberConverterFactory.ConverterNames);

            FromText = "0";
            ToText   = "0";

            FromConverterName = _numberConverterFactory.GetConverterName(_fromConverter);
            ToConverterName   = _numberConverterFactory.GetConverterName(_toConverter);

            ConvertCommand = new RelayCommand(ConvertNumbers);
        }