private void BackButton_Click(object sender, RoutedEventArgs e)
 {
     if (AktualnaStrona_Frame.CurrentSourcePageType != typeof(OperationsPage))
     {
         AktualnaStrona_Frame.Navigate(typeof(OperationsPage));
     }
 }
 private void NavigateIfDifferentPage(Type pageType)
 {
     if (AktualnaStrona_Frame.CurrentSourcePageType != pageType)
     {
         AktualnaStrona_Frame.Navigate(pageType);
     }
 }
        private void BackRequestedEvent(object sender, BackRequestedEventArgs e)
        {
            if (AktualnaStrona_Frame.CurrentSourcePageType == typeof(OperationsPage))
            {
                return;
            }

            AktualnaStrona_Frame.Navigate(typeof(OperationsPage));
            e.Handled = true;
        }
        private async void StatisticsAppBarRadioButton_Checked(object sender, RoutedEventArgs e)
        {
            CloseCommandBar();

            if (Statystyki_ListBoxItem != null)
            {
                Statystyki_ListBoxItem.IsChecked = true;
            }
            if (StatisticsAppBarRadioButton != null)
            {
                StatisticsAppBarRadioButton.IsChecked = true;
            }

            await Task.Delay(5);

            AktualnaStrona_Frame.Navigate(typeof(StatisticsPage));
        }
        private async void AddNewOperationAppBarRadioButton_Checked(object sender, RoutedEventArgs e)
        {
            CloseCommandBar();

            if (AddNewOperation_ListBoxItem != null)
            {
                AddNewOperation_ListBoxItem.IsChecked = true;
            }
            if (AddNewOperationAppBarRadioButton != null)
            {
                AddNewOperationAppBarRadioButton.IsChecked = true;
            }

            await Task.Delay(5);

            AktualnaStrona_Frame.Navigate(typeof(NewOperationPage));
        }
        private async void OperationsAppBarRadioButton_Checked(object sender, RoutedEventArgs e)
        {
            CloseCommandBar();

            if (Strona_glowna_ListBoxItem != null)
            {
                Strona_glowna_ListBoxItem.IsChecked = true;
            }
            if (OperationsAppBarRadioButton != null)
            {
                OperationsAppBarRadioButton.IsChecked = true;
            }

            await Task.Delay(5);

            if (AktualnaStrona_Frame.CurrentSourcePageType != typeof(OperationsPage))
            {
                AktualnaStrona_Frame.Navigate(typeof(OperationsPage));
            }
        }