C＃有私有和保护继承的概念？ [英] Does C# have the notion of private and protected inheritance?

问题描述

C＃有私人/保护继承的概念，如果没有，为什么？

Does C# have the notion of private / protected inheritance, and if not, why?

C ++

class Foo : private Bar {
 public:
   ...
 }; 

C＃

public abstract NServlet class : private System.Web.UI.Page
{
    // error "type expected"
}

我实施的servlet像概念一个.aspx页面，我不想具体类有看System.Web.UI.Page基地内部的能力。

I am implementing a "servlet like" concept in an .aspx page and I don't want the concrete class to have the ability to see the internals of the System.Web.UI.Page base.

推荐答案

C＃只允许公有继承。 C ++允许的所有三种。公有继承所隐含的IS-A型关系，而私有继承意味着A是实现多功能条件方面的一种关系。由于分层（或组合）来实现这一点的可以说是比较简单的方式，只有当经保护成员或虚函数绝对必要要求它使用私有继承 - 根据斯科特迈尔斯在有效的C ++项目42

C# allows public inheritance only. C++ allowed all three kinds. Public inheritance implied an "IS-A" type of relationship, and private inheritance implied a "Is-Implemented-In-Terms-Of" kind of relationship. Since layering (or composition) accomplished this in an arguably simpler fashion, private inheritance was only used when absolutely required by protected members or virtual functions required it - according to Scott Meyers in Effective C++, Item 42.

我的猜测是，C＃的作者没有感觉的另一个方面实现一个类是必要的这个额外的方法。

My guess would be that the authors of C# did not feel this additional method of implementing one class in terms of another was necessary.

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