扩展方法可以应用于接口吗？(Can extension methods be applied to interfaces?)

扩展方法可以应用于接口吗？(Can extension methods be applied to interfaces?)

可以将扩展方法应用于接口吗？ （C＃问题）

这是为了实现以下目的：

创建一个ITopology界面

为此接口创建一个扩展方法（例如public static int CountNodes（此ITopology拓扑结构））

那么当创建实现ITopology的类（例如MyGraph）时，它将自动地具有Count Nodes扩展。

这样，实现接口的类将不一定要有一个set类名称来与扩展方法中定义的类对齐。

Is it possible to apply an extension method to an interface? (C# question)

That is for example to achieve the following:

create an ITopology interface

create an extension method for this interface (e.g. public static int CountNodes(this ITopology topologyIf) )

then when creating a class (e.g. MyGraph) which implements ITopology, then it would automatically have the Count Nodes extension.

This way the classes implementing the interface would not have to have a set class name to align with what was defined in the extension method.

最满意答案

当然可以 大多数Linq是围绕接口扩展方法构建的。

接口实际上是扩展方法发展的推动力之一; 由于它们不能实现任何自己的功能，扩展方法是将实际代码与接口定义相关联的最简单方法。

有关IEnumerable<T>的扩展方法的整个集合，请参阅Enumerable类。 要实现一个，它与实现一个类相同：

public static class TopologyExtensions { public static void CountNodes(this ITopology topology) { // ... } }

就接口而言，扩展方法没有什么特别的区别; 扩展方法只是一种静态方法，编译器应用一些句法糖，使其看起来像方法是目标类型的一部分。

Of course they can; most of Linq is built around interface extension methods.

Interfaces were actually one of the driving forces for the development of extension methods; since they can't implement any of their own functionality, extension methods are the easiest way of associating actual code with interface definitions.

See the Enumerable class for a whole collection of extension methods built around IEnumerable<T>. To implement one, it's the same as implementing one for a class:

public static class TopologyExtensions { public static void CountNodes(this ITopology topology) { // ... } }

There's nothing particularly different about extension methods as far as interfaces are concerned; an extension method is just a static method that the compiler applies some syntactic sugar to to make it look like the method is part of the target type.