public static class EnumExtension
    {
        public static string GetDisplayName(this Enum enumValue)
        {
            return enumValue.GetType()
                            .GetMember(enumValue.ToString())
                            .First()
                            .GetCustomAttribute<DisplayAttribute>()
                            .GetName();
        }
    }

    // Generate members in cshtml
    // <select asp-for="Property" asp-items="Html.GetEnumSelectList<BookType>()" ></select>