.net - OO 模式 : Shared work between abstract base class and subclasses

Question

我有一个抽象基类 T ，来自哪个类 A和 B继承。我现在有一个操作(在 T 上)，它需要在 A 中稍微不同的实现和 B ，但大部分代码都是一样的。让我给你举个例子:有两种可能来实现类似 .Clone 的东西。方法:

Public MustInherit Class T
    Protected MustInherit Function _DoClone() As T

    Public Function Clone() As T
        Dim clone = Me._DoClone()    ' do the subclass-specific stuff '
        ... ' do the shared stuff '
    End Function
End Class

Public Class A
    Inherits T

    Protected Overrides Function _DoClone() As T
        ... ' do the subclass-specific stuff '
    End Function
End Class

或者

Public MustInherit Class T
    Protected Sub _DoClone(clone As T)
        ... ' do the shared stuff '
    End Function

    Public MustInherit Function Clone() As T
End Class

Public Class A
    Inherits T

    Public Overrides Function Clone() As T
        Dim clone = ... ' do the subclass-specific stuff '
        Me._DoClone(clone)
    End Function
End Class

(示例在 VB.NET 中，但同样的问题适用于 C#、Java 等。)

我的问题:

是否有明显首选的选项？

这是一个众所周知的模式，有一个名字(以便我可以做更多的研究)？

对于这种情况(即 _Do...)，是否有完善的命名约定？

Answer 1

看起来像 Template method图案:

The template method is used to:

• let subclasses implement (through method overriding) behavior that can vary
• avoid duplication in the code: you look for the general code in the algorithm, and implement the variants in the subclasses
• control at what point(s) subclassing is allowed.