public MainWindow() { InitializeComponent(); ((Storyboard)Resources["krecisiekolo"]).Begin(); ((Storyboard)Resources["krecisiekolo"]).Pause(); tokenSource = new CancellationTokenSource(); convertersCombobox.ItemsSource = new ConvertersService().GetConverter(); FilterByConverterName.ItemsSource = convertersCombobox.ItemsSource; this.Loaded += MainWindow_Loaded; //pobierz z bazy ocene aplikacji rateMe.Value = LogDBU.GetRateMeValue(); RelayCommand convertCommand = new RelayCommand(obj => Convert(), obj => convertersCombobox.SelectedItem != null && UnitToCombobox.SelectedItem != null && UnitFromCombobox.SelectedItem != null && string.IsNullOrEmpty(inputTextbox.Text) == false); convertButton.Command = convertCommand; }