private void textBox_KeyUp(object sender, System.Windows.Input.KeyEventArgs e) { bool found = false; var border = (resultStack.Parent as ScrollViewer)?.Parent as Border; var data = Prediction.Models(); string query = (sender as TextBox)?.Text; if (query.Length == 0) { resultStack.Children.Clear(); border.Visibility = System.Windows.Visibility.Collapsed; } else { border.Visibility = System.Windows.Visibility.Visible; } resultStack.Children.Clear(); foreach (var word in data) { if (word.ToLower().StartsWith(query.ToLower())) { addItem(word); found = true; } } }