带派生参数的派生类和覆盖方法:如何更好地编码？

Question

我有一个关于派生,多态和方法签名的问题

我有课

public abstract class PaymentMethod
{   
    public abstract float GetSalary (Employee employee,Vehicule vehicule)
}

和另外两个人

public class MarinePaymentMethod : PayementMethod
{
    public override float GetSalary (Sailor sailor,Boat boat)
}

public class AirPaymentMethod : PayementMethod
{
    public override float GetSalary (Pilot pilot,Plane plane)
}

我们还假设:

public class Sailor : Employee{}
public class Pilot : Employee{}
public class Boat: Vehicule{}
public class Plane: Vehicule{}

所以,"问题"是这个代码不能编译,因为签名不一样.

我强制保留基本签名GetSalary(员工员工,Vehicule vehicule)

然后我必须投在派生付款方式,这样我可以使用的特定成员Pilot,Sailor,Boat,Plane在这些具体的付款方式.

我的第一个问题是:连续投射不是难闻的气味吗？

我的第二个问题是:如何制作更优雅的代码设计？我在考虑Generics,并创建一个这样的类:

public abstract class PaymentMethod<T, U> where T: Employee where  U: Vehicule 

但是在我的代码中,我意识到我必须把泛型几乎放在我使用支付方法的所有地方,它会使代码变得沉重.还有其他方法吗？

非常感谢

Answer 1

就我个人而言，我会这样做：

public abstract  class PaymentMethod { 
    public decimal GetSalary(Employee employee, Vehicle vehicle) {
        return GetSalaryImpl(employee, vehicle);
    }    
    protected abstract decimal GetSalaryImpl(Employee employee, Vehicle vehicle);
}
public class MarinePaymentMethod : PaymentMethod {
    public decimal GetSalary(Sailor sailor,Boat boat)
    { throw new NotImplementedException(); /* your code here */ }
    protected override decimal GetSalaryImpl(Employee employee, Vehicle vehicle) {
        return GetSalary((Sailor)employee, (Boat)vehicle);
    }
}    
public class AirPaymentMethod : PaymentMethod {
    public decimal GetSalary(Pilot pilot, Plane plane)
    { throw new NotImplementedException(); /* your code here */ }
    protected override decimal GetSalaryImpl(Employee employee, Vehicle vehicle) {
        return GetSalary((Pilot)employee, (Plane)vehicle);
    }
}
public class Employee {}
public class Vehicle{}
public class Sailor : Employee{}
public class Pilot : Employee{}
public class Boat: Vehicle{}
public class Plane: Vehicle{}

这对于多态性和重载方法都适用——尽管采用 an 的方法Employee需要特定类型的员工是不常见的。