c# - .Net 4.0 重构现有 "if"条件和 "is"运算符的优化代码

Question

我有以下 C# 代码。它工作正常；但是 GetDestination() 方法通过使用 is operator 被多个 if 条件弄得乱七八糟。 .

在 .Net 4.0(或更高版本)中，避免这些“if”条件的最佳方法是什么？

编辑:角色是业务模型的一部分，目的地纯粹是使用该业务模型的特定应用程序的产物。

代码

public class Role { }
public class Manager : Role { }
public class Accountant : Role { }
public class Attender : Role { }
public class Cleaner : Role { }
public class Security : Role { }

class Program
{
    static string GetDestination(Role x)
    {
        string destination = @"\Home";

        if (x is Manager)
        {
            destination = @"\ManagerHomeA";
        }

        if (x is Accountant)
        {
            destination = @"\AccountantHomeC";
        }

        if (x is Cleaner)
        {
            destination = @"\Cleaner";
        }

        return destination;

    }

    static void Main(string[] args)
    {
        string destination = GetDestination(new Accountant());
        Console.WriteLine(destination);
        Console.ReadLine();
    }
}

引用文献

1. Dictionary<T,Delegate> with Delegates of different types: Cleaner, non string method names?
2. Jon Skeet: Making reflection fly and exploring delegates
3. if-else vs. switch vs. Dictionary of delegates
4. Dictionary with delegate or switch?
5. Expression and delegate in c#

Answer 1

具有在派生类中将被覆盖的virtual 属性应该可以解决问题:

class Role
{
    public virtual string Destination { get { return "Home"; } }
}
class Manager : Role
{
    public override string Destination { get { return "ManagerHome;"; } }
}
class Accountant : Role
{
    public override string Destination { get { return "AccountantHome;"; } }
}
class Attender : Role
{
    public override string Destination { get { return "AttenderHome;"; } }
}
class Cleaner : Role
{
    public override string Destination { get { return "CleanerHome;"; } }
}
class Security : Role { }

我没有将属性抽象化，以便在未在派生类中覆盖时提供默认的 Home 值。

用法:

string destination = (new Accountant()).Destination;
Console.WriteLine(destination);
Console.ReadLine();