// обработка нажатия элемента в списке
        private async void OnItemSelected(object sender, SelectedItemChangedEventArgs e)
        {
            BarecodeResult     selectedBarecode = (BarecodeResult)e.SelectedItem;
            BarecodeResultPage barecodePage     = new BarecodeResultPage();

            barecodePage.BindingContext = selectedBarecode;
            await Navigation.PushAsync(barecodePage);
        }
        // обработка нажатия кнопки добавления
        private async void CreateBarecode(object sender, EventArgs e)
        {
            BarecodeResult     result       = new BarecodeResult();
            BarecodeResultPage barecodePage = new BarecodeResultPage();

            result.Status   = 1;
            result.dateTime = DateTime.Now;

            barecodePage.BindingContext = result;
            await Navigation.PushAsync(barecodePage);
        }