public static int? ShowDialog(Window owner, bool tradeEvolve)
 {
     EvolutionTypeWindow window = new EvolutionTypeWindow(tradeEvolve);
     window.Owner = owner;
     var result = window.ShowDialog();
     if (result.HasValue && result.Value) {
         return window.selectedType;
     }
     return null;
 }
        public static int?ShowDialog(Window owner, bool tradeEvolve)
        {
            EvolutionTypeWindow window = new EvolutionTypeWindow(tradeEvolve);

            window.Owner = owner;
            var result = window.ShowDialog();

            if (result.HasValue && result.Value)
            {
                return(window.selectedType);
            }
            return(null);
        }