Question

我是F＃的新手，所以请怜悯。试图在F＃中模拟租车业务。我的类型是：
客户
司机
车
VehicleType
RentalAgreement 未实现

我的具体问题是，F＃类的成员是否是一个被歧视的联盟？汽车应该有一个属性，反映它是什么类型的车辆...紧凑型，轿车，卡车等...以下是我的代码到目前为止...

namespace DSL2

// a DU
type vehicleType =  Truck | Compact | Econ | Sedan

// a record
type Customer =  {firstName: string; lastName: string; gender: string}

//a class implicit ctor'tion
type Car(numdoors:int ,  make: string , year:int)  = class
    member this.NumDoors = numdoors
    member this.Make = make
    member this.Year = year  
end

//a class explicit ctor'tion
type Car2 = class
    val NumDoors: int
    val Make: string
    val Year: int

    (*first ctor*)
    new (numDoors, make, year) = 
        {NumDoors = numDoors; Make = make; Year = year}

 end

Answer 1

是的，一个有区别的联合就像任何其他类型一样，可以用作任何字段，属性，构造函数参数等的类型。

只需将vehicleType类型的参数添加到Car构造函数：

type Car(numdoors:int, make: string, year:int, vehicleType : vehicleType) = class
    member this.NumDoors = numdoors
    member this.Make = make
    member this.Year = year
    member this.VehicleType = vehicleType
end

请注意，使用小写字母命名类型是不好的F＃样式，因此我建议将其重命名为VehicleType。

Answer 2

是的，只需将该成员添加到该类中，并将其包含在具有所需值的构造函数中。

// a DU
type vehicleType =  Truck | Compact | Econ | Sedan

// a record
type Customer =  {firstName: string; lastName: string; gender: string}

//a class implicit ctor'tion
type Car(numdoors:int ,  make: string , year:int)  = class
    member this.NumDoors = numdoors
    member this.Make = make
    member this.Year = year  
end

//a class explicit ctor'tion
type Car2 = class
    val NumDoors: int
    val Make: string
    val Year: int
    val DU: vehicleType

    (*first ctor*)
    new (numDoors, make, year, cust) = 
        {NumDoors = numDoors; Make = make; Year = year;  DU = Truck }
 end

F＃租车业务模式

2 个答案: