namespace ValidationProgram
{
    public class testException : MyException
    {
        public override string Message
        {
            get
            {
                return "data type is incorrect";
            }
        }
    }
}


namespace ValidationProgram
{
    [Serializable]
    public class MyException : Exception
    {
        public MyException() { }
        public MyException(string message) : base(message) { }
        public MyException(string message, Exception inner) : base(message, inner) { }
        protected MyException(
          System.Runtime.Serialization.SerializationInfo info,
          System.Runtime.Serialization.StreamingContext context)
            : base(info, context) { }
    }

}



public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Validator_Click(object sender, RoutedEventArgs e)
        {



            try
            {


                //Validating Order

                XmlReaderSettings settings = new XmlReaderSettings();
                settings.Schemas.Add("OrderValidator.xsd");
                settings.ValidationType = ValidationType.Schema;


                XmlReader order = XmlReader.Create("order.xml", settings);
                XmlDocument xdoc = new XmlDocument();
                xdoc.Load(order);

                ValidationEventHandler handler = new ValidationEventHandler(ValidationEventHandler);

                xdoc.Validate(handler);


            }


            catch (MyException ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void ValidationEventHandler(object sender, ValidationEventArgs e)
        {
            throw new testException();
        }