避免如果其他条件

Question

我想重构以下代码以避免if ... else以便每次进入新的调查类型时都不必更改方法(开放/封闭原则).以下是我正在考虑重构的一段代码:

if (surveyType == SurveySubType.Anonymous)
{
    DoSomething(param1, param2, param3);

}
else if (surveyType == SurveySubType.Invitational)
{
    DoSomething(param1);
}
else if (surveyType == SurveySubType.ReturnLater)
{    
    DoSomething(param1);
}

为了解决这个问题,我添加了以下类:

    public abstract class BaseSurvey
{
            public string BuildSurveyTitle()
            {
             ...doing something here
            }

    public abstract void DoSomething(int? param1,int?  param2,int?  param3);
}
public class InvitationalSurvey: BaseSurvey
{
    public override void DoSomething(int? param1,int?  param2,int?  param3)
    {
    //I don't need param2 and param3 here

    }
}


public class ReturnLaterSurvey: BaseSurvey
{
    public override void DoSomething(int? param1,int?  param2,int?  param3)
    {
    //I don't need param2 and param3 here

    }
}


public class AnonymousSurvey: BaseSurvey
{
    public override void DoSomething(int? param1,int?  param2,int?  param3)
    {

    //I need param2 and param3 here
    //do something
    }

}

这就是我的代码最终结果:

var survey = SurveyFactory.Create();
survey.DoSomething(param1,param2,param3);

我的问题是避免将param2和param3传递给InvitationalSurvey和ReturnLaterSurvey类会有什么好处？

Answer 1

如果param2和param3是具体要求的AnonymousSurvey,他们不应该是接口的一部分,但具体类:

public abstract class BaseSurvey
{
    public abstract void DoSomething(param1);
}

public class InvitationalSurvey: BaseSurvey
{
    public void DoSomething(param1)
    {
    }
}


public class ReturnLaterSurvey: BaseSurvey
{
    public void DoSomething(param1)
    {
    }
}


public class AnonymousSurvey: BaseSurvey
{
    private readonly object param2;
    private readonly object param3

    public AnonymousSurvey(param2, param3)
    {
        this.param2 = param2;
        this.param3 = param3;
    }

    public void DoSomething(param1)
    {
        // use this.param2 and this.param3 here
    }
}

Answer 2

您发布的代码不是c#或java。不管怎样，听起来你想要一个Option type。