Azure Bot中的Attribute+Enum+流畅接口实现

在玩bot framework时，发现他的formflow这部分的设计不错，尤其是attribute和enum的结合使用非常完美。
以下为其代码设计：
 

public enum SandwichOptions    {        BLT, BlackForestHam, BuffaloChicken, ChickenAndBaconRanchMelt, ColdCutCombo, MeatballMarinara,        OvenRoastedChicken, RoastBeef, RotisserieStyleChicken, SpicyItalian, SteakAndCheese, SweetOnionTeriyaki, Tuna,        TurkeyBreast, Veggie    };    public enum LengthOptions { SixInch, FootLong };    public enum BreadOptions { NineGrainWheat, NineGrainHoneyOat, Italian, ItalianHerbsAndCheese, Flatbread };    public enum CheeseOptions { American, MontereyCheddar, Pepperjack };    public enum ToppingOptions    {        Avocado, BananaPeppers, Cucumbers, GreenBellPeppers, Jalapenos,        Lettuce, Olives, Pickles, RedOnion, Spinach, Tomatoes    };    public enum SauceOptions    {        ChipotleSouthwest, HoneyMustard, LightMayonnaise, RegularMayonnaise,        Mustard, Oil, Pepper, Ranch, SweetOnion, Vinegar    };    [Serializable]    public class SandwichOrder    {        public SandwichOptions? Sandwich;        public LengthOptions? Length;        public BreadOptions? Bread;        public CheeseOptions? Cheese;        public List<ToppingOptions> Toppings;        public List<SauceOptions> Sauce;        public static IForm<SandwichOrder> BuildForm()        {            return new FormBuilder<SandwichOrder>()                    .Message("Welcome to the simple sandwich order bot!")                    .Build();        }    };return new FormBuilder<SandwichOrder>()                        .Message("Welcome to the sandwich order bot!")                        .Field(nameof(Sandwich))                        .Field(nameof(Length))                        .Field(nameof(Bread))                        .Field(nameof(Cheese))                        .Field(nameof(Toppings),                            validate: async (state, value) =>                            {                               //..                                return result;                            })                        .Message("For sandwich toppings you have selected {Toppings}.")                        .Field(nameof(SandwichOrder.Sauces))                        .Field(new FieldReflector<SandwichOrder>(nameof(Specials))                            .SetType(null)                            .SetActive((state) => state.Length == LengthOptions.FootLong)                            .SetDefine(async (state, field) =>                            {                                field                                    .AddDescription("cookie", "Free cookie")                                    .AddTerms("cookie", "cookie", "free cookie")                                    .AddDescription("drink", "Free large drink")                                    .AddTerms("drink", "drink", "free drink");                                return true;                            }))                        .Confirm(async (state) =>                        {                            //..                            return new PromptAttribute($"Total for your sandwich is {cost:C2} is that ok?");                        })                        .Field(nameof(SandwichOrder.DeliveryAddress),                            validate: async (state, response) =>                            {                                //..                                return result;                            })                        .Field(nameof(SandwichOrder.DeliveryTime), "What time do you want your sandwich delivered? {||}")                        .Confirm("Do you want to order your {Length} {Sandwich} on {Bread} {&Bread} with {[{Cheese} {Toppings} {Sauces}]} to be sent to {DeliveryAddress} {?at {DeliveryTime:t}}?")                        .AddRemainingFields()                        .Message("Thanks for ordering a sandwich!")                        .OnCompletion(processOrder)                        .Build();

在以上代码中，
1. 使用了enum来定义选项信息
2. 使用attribute来做model和enum的粘合剂
3. FormBuilder的流程接口来完成对话的创建
4. FormBuilder通过对分组提问来构造不同的orderDetail对象

...Message(..).Field()....Message("").Field(...)..