private void OnClick(object sender, RoutedEventArgs e)
        {
            File.WriteAllText("YourXaml.xaml", txtXamlData.Text);
            Window myWindow = null;
            try
            {
                using (Stream sr = File.Open("YourXaml.xaml", FileMode.Open))
                {
                    myWindow = (Window)XamlReader.Load(sr);
                    myWindow.ShowDialog();
                    myWindow.Close();
                    myWindow = null;
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }