c# 设计模式 - 与 Base 交互

Question

我有一个类 SafeChargeDeposit 继承自 BaseExternalDeposit。
BaseExternalDeposit 在其构造函数中需要一个变量类型 BaseDepositStructure。

因为它需要 BaseDepositStructure，所以我不能在 SafeChargeDeposit 中使用它的子元素。

这是代码:

 abstract class BaseExternalDeposit
    {
        public abstract BaseExternalDepositResult DoDeposit();

        protected BaseDepositStructure depositStructure;

        public BaseExternalDeposit(BaseDepositStructure depositStructure)
        {
            this.depositStructure = depositStructure;
        }
    }


 class SafeChargeDeposit : BaseExternalDeposit
 {
       public SafeChargeDeposit(CreditCardDepositStructure depositStructure):base(depositStructure){}

       public override BaseExternalDepositResult DoDeposit(){

        /////// I CAN USE THIS MEMBER:
        depositStructure.Amount = 50;

        /////// BUT I CANNOT USE THIS MEMBER:
        depositStructure.CreditCardNumber = "123456"; 
       }
 }


public class BaseDepositStructure
    {
        public double Amount = 0.0;
    }

    public class CreditCardDepositStructure : BaseDepositStructure
    {
        public string CreditCardNumber = string.Empty;
    }

我明白为什么我可以使用 depositStructure.Amount 而不能使用 depositStructure.CreditCardNumber ...但是我这里的设计有什么问题呢？我怎样才能解决这个问题并保持使用 Bases 的灵 active 。

Answer 1

interface IBaseExternalDepositResult
{
};  // eo interface BaseExternalDepositResult

interface IDeposit
{
    void Deposit();
};

// class BaseExternalDeposit<>
abstract class BaseExternalDeposit<B> : IDeposit where B : BaseDepositStructure
{
    private B depositStructure_;
    protected abstract IBaseExternalDepositResult DepositImpl();
    protected B Structure { get { return depositStructure_; } }

    public BaseExternalDeposit(B depositStructure)
    {
        depositStructure_ = depositStructure;
    }   // eo ctor


    // IDeposit
    void Deposit()
    {
        DepositImpl();
    }
}   // eo class BaseExternalDeposit<B>


// class SafeChargeDeposit
class SafeChargeDeposit : BaseExternalDeposit<CreditCardDepositStructure>
{
    protected override IBaseExternalDepositResult DepositImpl()
    {
        Structure.Amount = 50;
        Structure.CreditCardNumber = "123456";
    }   // eo DepositImpl


    public SafeChargeDeposit(CreditCardDepositStructure depositStructure)
        : base(depositStructure)
    {
    }
}   // eo class SafeChargeDeposit


public class BaseDepositStructure
{
    public double Amount = 0.0;
}

public class CreditCardDepositStructure : BaseDepositStructure
{
    public string CreditCardNumber = string.E