C# 工厂返回接口

我正在创建一个票务系统，其中一个请求由用户提交，最终由SME响应。在这个系统中可以提出两种类型的请求；支持硬件查询和备用驱动程序查询

由于它们具有相似的特性，我创建了一个名为IRequest的接口

public interface IRequest
{
    int RequestId { get; }
    State State { get; }
    RequestHeader RequestHeader { get; }
    InterimDialogue InterimDialogue { get; }       
    RequestSolution RequestSolution { get; }
}

在两种请求类型略有不同的地方，我创建了两个单独的接口，它们都实现了IRequest

SupportHardwarequiry的接口如下所示

public interface ISupportHardwareEnquiry : IRequest
{
    SupportingInformation SupportingInformation { get; }
    ProblemTask ProblemTask { get; }
}

最后，具体的类实现了ISupportHardwareEnquiry

public class SupportHardwareEnquiry : ISupportHardwareEnquiry
{     
    public int RequestId { get; private set; }
    public State State { get; private set; }
    public RequestHeader RequestHeader { get; private set; }
    public SupportingInformation SupportingInformation { get; private set; }
    public ProblemTask ProblemTask { get; private set; }
    public InterimDialogue InterimDialogue { get; private set; }
    public RequestSolution RequestSolution { get; private set; }

 // etc ...
}

为了实例化SupportHardwareRequesty对象，使用了RequestFactory

public class RequestFactory : IRequestFactory
{
    public IRequest CreateSupportHardwareEnquiry()
    {
        return new SupportHardwareEnquiry();
    }


    public IRequest CreateAlternateDriverEnquiry()
    {
        return new AlternateDriverEnquiry();
    }
}

我还使用存储库列出请求，并重新组织单个请求

public interface IRequestRepository
{
    IEnumerable<IRequest> GetAllRequests();


    IRequest GetAlternateDriverEnquiry(int id);


    IRequest GetSupportHardwareEnquiry(int id);
}

但是现在我知道我需要提前知道，我想得到什么，剩下的似乎没有多大意义

---

我知道我可以使用继承来代替，但是当我有时想将这些设计情况视为一般请求，有时又想将其视为特定类型的请求时，我应该如何处理这些设计情况呢？

如果CreateSupportHardwarequiry（）总是会返回IsupperWarequiry，只需在方法定义中键入Hint即可

public class RequestFactory : IRequestFactory
{
    public ISupportHardwareEnquiry CreateSupportHardwareEnquiry()
    {
        return new SupportHardwareEnquiry();
    }


    public IRequest CreateAlternateDriverEnquiry()
    {
        return new AlternateDriverEnquiry();
    }
}

public class RequestFactory : IRequestFactory
{
    public ISupportHardwareEnquiry CreateSupportHardwareEnquiry()
    {
        return new SupportHardwareEnquiry();
    }


    public IRequest CreateAlternateDriverEnquiry()
    {
        return new AlternateDriverEnquiry();
    }
}