/// <summary> /// Check if string is all numerals /// If not reset value to '00' /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void TextboxValueCheck(object sender, TextChangedEventArgs e) { TextBox txt = (TextBox)sender; if (!HelperMethods.AreAllValidNumericChars(txt.Text)) { txt.Text = "00"; txt.CaretIndex = txt.Text.Length; } }