//Добавление продукта в список
private async void AddItemTextBox_KeyUp(object sender, KeyRoutedEventArgs e)
{
if (e.Key == Windows.System.VirtualKey.Enter)
{
if (this.AddItemTextBox.Text != "")
{
await SampleDataSource.AddItem(this.AddItemTextBox.Text);
this.AddItemTextBox.Text = "";
}
else
{
await new MessageDialog(App.resourceLoader.GetString("AddEmptyItemError")).ShowAsync();
}
}
}