private void Power(object sender, RoutedEventArgs e) { String inputDataA = tbA.Text; String inputDataB = tbB.Text; try { double dataA = Double.Parse(inputDataA); double dataB = Double.Parse(inputDataB); Others s = new Others(dataA, dataB); double result = s.Power(); resultat.Text = result.ToString(); } catch (Exception) { MessageBox.Show("Numbers, Mayson, what are they meaning?..", "Error", MessageBoxButton.OK, MessageBoxImage.Error); } }